RU2740782C1 - Method of radar surveying of earth and near-earth space by radar with synthesized antenna aperture in band with ambiguous range with selection of moving targets on background of reflections from underlying surface and radar with synthesized antenna aperture for implementation thereof - Google Patents

Abstract

FIELD: physics.SUBSTANCE: invention relates to the field of radar ranging and is intended for use in the development of airborne and comic-based synthetic aperture radars (SAR). Radar with synthesized antenna aperture, which realizes method of radar survey of Earth and near-Earth space in range ambiguous in range with selection of moving targets on background of reflections from underlying surface, contains: bank of pulsed characteristics of range coordinated filter (CF), five blocks of fast Fourier transform (FFT), digital probing radio signal generator, analogue-to-digital receiving-transmitting antenna-amplification system, digital radio hologram memory unit (DRH), a unit for dividing range elements into groups, seven multipliers, a unit for calculating a three-dimensional array of pulsed characteristics of azimuth CF, four units of inverse FFT, two units for combining groups of range elements, a unit for calculating correction functions, two units for calculating amplitudes, an indicator of the underlying surface, a recrampling unit for correcting the period of sampling the azimuth signals, a unit for calculating a four-dimensional array of pulsed characteristics of the azimuthal CF for all values of the radial velocity Vr, a unit for calculating azimuthal rate corrected Vx, a unit for calculating a four-dimensional array of common thresholds, a unit for calculating a four-dimensional array of local thresholds, a unit for calculating a four-dimensional array of peaks of neighboring elements, a unit for calculating a four-dimensional array of maximum thresholds, a unit of a comparator, a unit for calculating maximum values of a four-dimensional array of pixels of radar images detected by a radar detector along the dimensions of radial Vr and azimuthal Vx velocities, an indicator of a DC.EFFECT: technical result is construction of a radar image (RI) of a fixed underlying surface and detection of moving targets (MT) on a background of reflections from the underlying surface in a wide range of ambiguous shooting band using ultra-wideband probing radio pulses with a period of repetition and wave form varied from radio pulse to radio pulse and minimum loss of radar potential tending to decibel as the pulse duration of probing radio pulses increases.2 cl, 12 dwg

Description

The invention relates to the field of radar and is intended for use in the creation of radars with a synthetic aperture antenna (SAR) air and comic-based. The achieved technical result is the construction of a radar image (RI) of a stationary underlying surface and the detection of moving targets (DC) against the background of reflections from the underlying surface in a wide, ambiguous range of survey band when using ultra-wideband sounding radio pulses with a repetition period and waveform varying from radio pulse to radio pulse and the minimum loss of radar potential, tending to zero decibels with increasing duty cycle of sounding radio pulses.

An unambiguous shooting strip is a strip, all the reflected radio signals from which are located on the time axis in one receiving strobe, the duration of which does not exceed the time between the cut of the current and the front of the next probing radio pulses. In this case, the periods of sounding, in which the reception of the reflected radio signal occurs, may not coincide with the periods of radiation of the sounding radio signal. An ambiguous shooting strip is a strip for which the reflected radio signals are located in time in two or more receiving gates or, in other words, fall within two or more repetition periods of sounding radio pulses [1, 2].

The waveform of a radio pulse, referred to as "waveform" in foreign literature, is understood as "a geometric shape that is obtained by displaying the characteristics of a wave as a function of some variable, usually time" [1]. In particular, an oscillogram of a radio pulse, a function that displays the dependence of the instantaneous value of a signal on time, falls under this definition. The form of this function depends, among other things, on intra-pulse phase, frequency and amplitude modulation and on the carrier frequency of the radio pulse.

The radar potential is understood as the value determined by the formula [1,3]:

where q is the specified signal-to-noise ratio at the output of the matched radar filter;

R _max is the maximum target detection range with a given effective scattering area (ESR);

σ _Ц - target RCS set.

Resampling refers to the process of taking samples of some digitized signal at other points in time that do not coincide with the original ones. Resampling is usually implemented using Digital Fractional Delay Filters, the most common of which is the Farrow filter [4 ... 12].

The known method of longitudinal interferometry along the track and realizing it PC A [13]. This method is implemented when using an active phased array antenna (APAR), divided into two or more sections, in SAR. When using a two-section antenna for transmission, signals from both sections are summed up, and reception and processing are carried out independently for each section. In each of the two receiving channels (A and B), the radio signal received by the antenna section is amplified, transferred to the base frequency region and digitized, after which complex RLI (RLI) are formed, - two-dimensional arrays, represented by complex readings, and the process of RLI formation in channel A is delayed for the repetition period of the probing radio pulses Tzri. After receiving CRLI in channels A and B, the CRLI data is summed up in the adder and subtracted in the subtractor. At the output of the adder, the total QRL is obtained, and at the output of the subtractor, the differential QRL. The removed underlying surface, stationary and moving targets are present on the total CRLI, and on the differential CRLI - only radially moving targets, which are detected further in the detector of moving targets by threshold processing. Then the velocities of the detected moving targets are calculated and the azimuth coordinates of the moving targets are corrected.

A SAR that implements this method contains: a probe radio signal generator, divided into two sections, a transceiving AFAR, two digital receivers, two QRLI shapers, a delay unit for time Tzri, an adder, a subtractor, a moving target detector and a calculator for the speed of moving targets and corrections to the azimuth coordinate ...

The disadvantages of this method and device are:

- the need to use two receiving positions formed by the halves of the AFAR antenna curtain, which leads to a decrease in the radar potential and, consequently, to a deterioration in the quality of the survey;

- detection of only radially moving targets;

- the presence of blind speeds, at which the phase difference between the complex signals of the interferometric channels is a multiple of 2π, and moving targets are not detected;

- a fixed value of the repetition rate of sounding radio pulses, which makes it possible to survey only in a narrow, unambiguous survey band in terms of range.

The known method of spatial frequency filtering (PSF) and realizing it SAR [14 ... 16]. This method is implemented using an antenna device with three beams partially overlapping in the azimuth plane. The central beam, directed normal to the ground speed vector, is connected to the transmitter and used to emit a sounding radio signal. Radio signals reflected from the underlying surface are received through the side beams, deflected forward and backward at a certain angle not exceeding half of the radiation pattern width, which are further amplified in two independent receivers, at the outputs of which amplified radio signals are digitized using analog-to-digital converters ADC-1 and ADC-2. Then, radar images are synthesized in each channel, including, at the first stage, range compression with migration compensation. Next, compression is performed in azimuth using a fast convolution algorithm, which generally includes a fast Fourier transform (FFT) in azimuth, multiplication by a reference function, and inverse FFT. In the case under consideration, SAR with the selection of moving targets (MTS), the phase functions of the reference spectrum in each channel are matched with the received radio signal, and the envelopes of the reference spectra are made different. When the received signals are compressed in azimuth, the Doppler frequency spectrum of signal S1 is multiplied by the reference function Kf1, the envelope of which coincides with the envelope of the Doppler spectrum of the signal S2, and vice versa, the Doppler spectrum of the signal S2 is multiplied by the reference function Kf2, the envelope of which coincides with the envelope of the Doppler spectrum of the signal S1 ... As a result, the Doppler spectra of the signals of both channels for stationary targets and the terrain background coincide. Next, the difference between the two received radar images is calculated. The radar images obtained after compression in azimuth and detection for stationary targets are identical and are compensated for when subtracted. For moving targets, the envelopes of the Doppler spectra of the received radio signals are shifted, which leads to a difference in the amplitudes of the synthesized radar images and, when subtracted, gives a radar image difference that is nonzero and proportional to the target speed. The sum and difference radar images are fed to a unit that calculates the coordinates and speeds of targets.

A SAR that implements this method contains: a transmitter, an antenna device with three beams partially overlapping in the azimuthal plane, two digital receivers with analog-to-digital converters at the output, two radar data synthesis units with different reference spectra, a total radar data calculation unit, a differential radar data calculation unit , calculator of coordinates and speed of targets.

The disadvantages of this method and device are:

- selection of only radially moving targets, tangentially moving targets are not distinguished;

- loss of SAR potential due to operation on slopes of receiving directional diagrams (DP), turned from the central direction of the transmitting beam;

- reduction of the effective length of the synthesized aperture due to the mutual rotation of the receiving patterns and, as a consequence, the deterioration of the potential azimuth resolution;

- loss of SAR potential due to the addition of mutually incoherent noises of two receiving channels and the use of incoherent processing;

- loss of SAR potential at high radial target velocities that go beyond the discriminatory characteristics of the PFC algorithm.

The known method of differential defocusing for the detection of moving targets by the tangential component of the velocity and realizing it SAR [14]. When using this method, a sounding radio signal is generated and radiated in the direction of the underlying surface being removed through the receiving-transmitting antenna. The radio signal reflected from the underlying surface is received through the same antenna, amplified, digitized and compressed in range. Then the received signal is compressed in azimuth in two independent channels with different reference functions, shifted by the values of the ground speed by a certain defocusing step ΔVx. The radar images obtained in the channels are summed up, obtaining the total radar image, and subtracted, obtaining the difference radar image. Further, the total radar image and the difference radar image are multiplied, and moving targets are detected in the resulting radar image.

A PCA that implements this method comprises: a transmitter, a transmitting-receive antenna, a digital receiver, a range compression unit, two azimuth compression units with different reference functions shifted by ground speed values, a total radar data calculation unit, a differential radar data calculation unit, a radar data multiplication unit , a detector of moving targets.

The disadvantages of this method and device are:

- selection of only tangentially moving targets, radially moving targets are not distinguished;

- loss of SAR potential for all tangential target velocities other than the defocusing step ΔVx, especially at high tangential target velocities that go beyond the discriminatory characteristics of the considered method;

- deterioration of the characteristics of the generated total radar image due to defocusing.

The known method of radar survey, using a range-Doppler ("Range-Doppler") algorithm [17 ... 24], and realizing it RSA, Fig. one.

When using this method, a sounding radio signal with a fixed repetition period of the same radio pulses is generated and radiated in the direction of the underlying surface being removed through the transmitting and receiving antenna. The radio signal reflected from the underlying surface is received through the same antenna, amplified, and digitized. Thus, the initial data or digital radio hologram (TsRH), - a two-dimensional array of complex samples U _in (tr, tx), is obtained. The numbers along the first (vertical) dimension of this array (fast time tr) correspond to the elements (discretes) of the slant range, and the numbers along the second (horizontal) dimension (slow time tx) correspond to the azimuth elements, each of which, in turn, corresponds to its own sounding radio pulse. Then, FFT is performed along the slant range (along the fast time tr) for each column of the CRG U _in (tr, tx). After that, each column of the obtained two-dimensional array S _in (ƒr, tx) of the range spectra of the DGC is multiplied by the column of the reference spectrum of the range matched filter (SF) S _RMFreƒ (ƒr), obtained by taking the FFT from the column H _RMF (tr) of the impulse response of the range SF for the used sounding radio pulse. As a result, a two-dimensional array S _RC (ƒr, tx) of the range spectra of a range-compressed CRG is obtained, which, after the inverse FFT along the frequency ƒr, is converted into a two-dimensional array of a range-compressed CRG U _RC (tr, tx). Then a line-by-line FFT is performed along the slow time tx over the rows of this array and a two-dimensional array S _RC (tr, ƒc) of azimuthal spectra of the range-compressed CRG is obtained, after which, by resampling [4 ... 12], the signal migration is corrected by range elements (Range Cell Migration Correction - RCMC) and obtain a two-dimensional array S _RCMC (tr, ƒx) of the azimuthal spectra of the range-compressed CRG with corrected migration along the range elements.

Calculate a two-dimensional array S _AMFreƒ (tr, tx) of the impulse characteristics of the azimuthal SF and perform line-by-line FFT along the slow time tx of this array, thus obtaining a two-dimensional array S _AMFreƒ (tr, ƒx) of the reference spectra of the azimuthal SF. The two-dimensional array S _RCMC (tr, ƒx) of the azimuthal spectra of the range-compressed CRG with the corrected migration by range elements is elementwise multiplied by the two-dimensional array S _AMFreƒ (tr, ƒx) of the reference spectra of the azimuthal SF, thus obtaining a two-dimensional array S _AMFout (tr, ƒx) azimuthal spectra of the azimuthal SF output signal. The inverse FFT is calculated line by line along the frequency ƒx of the specified array, a two-dimensional array U _RLI (tr, tx) of complex samples of the _{radar image of the} underlying surface is obtained, and the amplitudes of the complex samples of this array are calculated. A two-dimensional array I _RLI (tr, tx) of the _{radar image of the} underlying surface is obtained, which is displayed on the radar image of the underlying surface.

PCA that implements this method contains (Fig. 1):

- bank of impulse characteristics of long-range SF;

- the first FFT block along the fast time tr;

- digital generator of the probing radio signal;

- analog-digital receiving and transmitting antenna-amplifying system;

- memory block TsRG;

- the second FFT block along the fast time tr;

- the first block of multiplication;

- block of inverse FFT along the frequency ƒr;

- the first block of the FFT along the slow tx time;

- block for correction of signal migration by range elements (RCMC);

- block for calculating the impulse characteristics of the azimuthal SF;

- the second block of FFT along the slow tx time;

- the second block of multiplication;

- block of inverse FFT along the frequency ƒx;

- block for calculating amplitudes;

- radar image indicator of the underlying surface.

The disadvantages of this method and device are:

- high level of side lobes of the formed radar image with significant signal migration along the range [25];

- blurring and displacement of marks from moving targets on the received radar image, making it difficult to detect and distorting the coordinates of moving targets;

- a narrow range of shooting, the width of which is determined by the repetition period of sounding radio pulses;

- imposition on the useful radio signal, reflected from the range being taken, of interfering parasitic radio signals reflected from other, near and far sections of the range, falling into adjacent repetition periods of sounding radio pulses, which leads to distortion of the received radar image.

The known method of radar survey using the "Omega-k" (or "wavenumber") algorithm [22, 26 ... 31], and realizing it RSA, Fig. 2, chosen as a prototype.

When using this method

store the column H _RMF (tr) of the impulse response of the range SF for the used sounding radio pulse,

form a sounding radio signal with a fixed repetition period of the same sounding radio pulses corresponding to the impulse response stored in the column H _RMF (tr) of the impulse response of the range SF for the used sounding radio pulse, and emit this radio signal in the direction of the underlying surface being removed using an analog-digital transceiver antenna-amplifier systems,

the radio signal reflected from the underlying surface is received by means of an analog-to-digital receiving-transmitting antenna-amplifying system and the CRG U _in (tr, tx) is obtained, which is a two-dimensional array of complex readings, where tr is the fast time along the slant range r, and tx is the slow time along the azimuthal coordinate x,

CRG U _in (tr, tx) is divided along the fast time tr into N _RG groups of readouts along the slant range, thus obtaining a three-dimensional array of complex readouts U _in (tr, tx, n _RG ), where n _RG is the number of the group of readouts by the slant range which is also the number of pages in the specified three-dimensional array,

in each group of readouts along the slant range in a three-dimensional array of complex readouts U _in (tr, tx, n _RG ), an FFT is performed along the fast time tr for each column of readings and a three-dimensional array S _in (ƒr, tx, n _RG ) of range spectra is obtained CRG, where ƒr is the range frequency,

FFT is performed from the stored column H _RMF (tr) of the impulse response of the range SF for the used probing radio pulse, and the column S _AMFreƒ (ƒr) of the reference spectrum of the range SF is obtained, the columns of the three-dimensional array S _in (ƒr, tx, n _RG ) of the range spectra of the CRG are obtained element by element multiply by the column S _AMFreƒ (ƒr) of the reference spectrum of the range SF, thus obtaining a three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG,

FFT is performed along the slow time tx of the three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG, thus obtaining a three-dimensional array S _RC (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the range-compressed CRG,

calculate a three-dimensional array of impulse responses of the azimuthal SF

Where

- the multiplier of blanking the temporary support function;

- normalized end-to-end antenna pattern of the SAR antenna;

- мнимая единица;

- imaginary unit;

- the reference phase function of the azimuthal SF versus the slow time tx for the range frequency ƒr and the number of the group of range elements n _RG ;

- центральное значение медленного времени tx;

- the central value of the slow time tx;

T _CA - time of synthesis of the aperture;

ΔΘ _GL0 is the width of the main lobe (GL) of the SAR antenna antenna at the zero power level;

V _SGL is the speed of movement of the GL track of the AP antenna of the SAR on the underlying surface;

R ₀ (n _RG ) - traverse slant range of the center of the group of range elements with the number n _RG ;

c is the speed of propagation of electromagnetic waves in vacuum;

ƒ _ЗPC - carrier frequency of the probing radio signal;

perform line-by-line FFT along the slow time tx of the three-dimensional array S _AMFreƒ (ƒr, tx, n _RG ) of the impulse characteristics of the azimuthal SF, thus obtaining the three-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG ) of the reference two-dimensional spectra of the azimuthal SF,

the three-dimensional array S _RC (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the range-compressed CRG is elementwise multiplied by the three-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG ) of the reference two-dimensional spectra of the azimuthal SF, and a three-dimensional array S _AMFout (ƒr, ƒx , n _RG ) of the two-dimensional spectra of the azimuthal SF output signal,

column-wise inverse FFT of the three-dimensional array S _AMFout (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the output signal of the azimuthal SF along the frequency ƒr is performed, thus obtaining the three-dimensional array S _AMFout (tr, ƒх, n _RG ) of the azimuthal spectra of the output signal of the azimuthal SF,

pages of the three-dimensional array S _AMFout (tr, ƒx, n _RG ) of the azimuthal spectra of the azimuthal SF output signal are aligned along the first dimension - fast time tr, thus obtaining a two-dimensional array S _AMFout (tr, ƒx) of the azimuthal spectra of the azimuthal SF output signal,

calculate a two-dimensional array of correcting functions

where λ is the wavelength of the probing radio signal;

R ₀ (n _RSG ) traverse slant range of the center of the subgroup of range elements with number n _RSG ;

ƒx is the frequency of the azimuthal signal along the slow tx time;

the two-dimensional array S _AMFout (tr, ƒx) of the azimuthal spectra of the azimuthal SF output signal is multiplied line by line by the two-dimensional array S _corr (tr, ƒx) of the correcting functions, and a two-dimensional array S _AMFoutcorr (tr, ƒx) of the corrected azimuthal spectra is obtained,

calculate the inverse FFT line by line along the frequency ƒx of the two-dimensional array S _AMFoutcorr (tr, ƒx) of the corrected azimuthal spectra, thus obtaining a two-dimensional array U _RLI (tr, tx) of complex readouts of the radar image (RI) of the underlying surface,

calculate the amplitudes of the complex _{readouts of the} two-dimensional array U _RLI (tr, tx) of the complex _{readouts of the radar image of the} underlying surface, thus obtaining a two-dimensional array of pixels of the radar image of the underlying surface

a two-dimensional array I _RLI (tr, tx) of the _{radar image of the} underlying surface is displayed on the radar image of the underlying surface.

A PCA implementing this method comprises, FIG. 2:

- bank of impulse characteristics of long-range SF;

- the first FFT block along the fast time tr;

- digital generator of the probing radio signal;

- analog-digital receiving and transmitting antenna-amplifying system;

- memory block TsRG;

- block for dividing range elements into groups;

- the second FFT block along the fast time tr;

- the first block of multiplication;

- the first block of the FFT along the slow tx time;

block for calculating a three-dimensional array of impulse characteristics of the azimuthal SF;

- the second block of FFT along the slow tx time;

- the second block of multiplication;

- the first block of the inverse FFT along the frequency ƒr;

- the first block for combining groups of range elements;

- block for calculating corrective functions;

- the third block of multiplication;

- the first block of the inverse FFT along the frequency ƒx;

- the first block for calculating the amplitudes;

- radar image indicator of the underlying surface.

The disadvantages of this method and device are:

- blurring and displacement of marks from moving targets on the received radar image, making it difficult to detect and distorting the coordinates of moving targets;

- a narrow range of shooting, the width of which is determined by the repetition period of sounding radio pulses;

- imposition on the useful radio signal, reflected from the range being taken, of interfering parasitic radio signals reflected from other, near and far sections of the range, falling into adjacent repetition periods of sounding radio pulses, which leads to distortion of the received radar image.

The invention is aimed at ensuring the construction of radar images of a stationary underlying surface and detection of DCs against the background of reflections from the underlying surface in a wide, ambiguous range of survey range when using ultra-wideband sounding radio pulses with a repetition period and waveform varying from radio pulse to radio pulse and a minimum loss of radar potential tending to zero decibels with an increase in the duty cycle of the sounding radio pulses.

This is achieved by the fact that

- during the survey, the repetition period and the waveform of the sounding radio pulses are changed from the radio pulse to the radio pulse;

- with coordinated filtering of the radio signal reflected from the underlying surface in terms of range, impulse characteristics corresponding to the radiated radio pulses are fed to the long-range SF;

- before applying the processed signal to the azimuth SF, the sampling period of the azimuth signal along the slow time axis tx is corrected by resampling;

- azimuthal matched filtering is carried out for all possible combinations of values (hypotheses) on the plane of radial Vr and azimuthal Vx velocities of detected DCs, thus forming radar images for each combination of hypotheses and obtaining a 4-dimensional array of pixels of radar images;

- in the resulting 4-dimensional array, point DCs are detected using an extended detection algorithm with a constant false alarm rate (CFAR), [32, 33];

- display the detected DC on the moving target indicator.

The invention (method) differs from the closest known analogue [22, 26 ... 31], in which

store the column H _RMF (tr) of the impulse response of the range SF for the used sounding radio pulse,

form a sounding radio signal with a fixed repetition period of the same sounding radio pulses corresponding to the impulse response stored in the column H _RMF (tr) of the impulse response of the range SF for the used sounding radio pulse, and emit this radio signal in the direction of the underlying surface being removed using an analog-digital transceiver antenna-amplifier systems,

the radio signal reflected from the underlying surface is received using an analog-to-digital receiving-transmitting antenna-amplifying system and the CRG U _in (tr, tx) is obtained,

The CRG U _in (tr, tx) is divided along the fast time tr into NRG groups of readouts along the slant range, and a three-dimensional array of complex readouts U _in (tr, tx, n _RG ) is obtained,

in each group of readouts along the slant range in a three-dimensional array of complex readouts U _in (tr, tx, n _RG ), an FFT is performed along the fast time tr for each column of readings and a three-dimensional array S _in (ƒr, tx, n _RG ) of range spectra is obtained TsRG,

FFT is performed from the stored column H _RMF (tr) of the impulse response of the long-range SF for the used sounding radio pulse, and the column S _AMFreƒ (ƒr) of the reference spectrum of the long-range SF is obtained,

columns of the three-dimensional array S _in (ƒr, tx, n _RG ) of the range spectra of the CRG are elementwise multiplied by the column S _AMFreƒ (ƒr) of the ogur spectrum of the range SF, thus obtaining a three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra compressed in range TsRG,

FFT is performed along the slow time tx of the three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG, thus obtaining a three-dimensional array S _RC (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the range-compressed CRG,

calculate a three-dimensional array of impulse responses of the azimuthal SF S _AMFreƒ (ƒr, tx, n _RG ),

perform line-by-line FFT along the slow time tx of the three-dimensional array S _AMFreƒ (ƒr, tx, n _RG ) of the impulse characteristics of the azimuthal SF, thus obtaining the three-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG ) of the reference two-dimensional spectra of the azimuthal SF,

the three-dimensional array S _RC (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the range-compressed CRG is elementwise multiplied by the three-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG ) of the reference two-dimensional spectra of the azimuthal SF, and a three-dimensional array S _AMFout (ƒr, ƒx , n _RG ) of the two-dimensional spectra of the azimuthal SF output signal,

a column-wise inverse FFT of the three-dimensional array S _AMFout (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the output signal of the azimuthal SF along the frequency ƒr is performed, thus obtaining a three-dimensional array S _AMFout (tr, ƒx, n _RG ) of the azimuthal spectra of the output signal of the azimuthal SF,

pages of the three-dimensional array S _AMFout (tr, ƒx, n _RG ) of the azimuthal spectra of the azimuthal SF output signal are aligned along the first dimension - fast time tr, thus obtaining a two-dimensional array S _AMFout (tr, ƒx) of the azimuthal spectra of the azimuthal SF output signal,

calculate a two-dimensional array of correcting functions S _corr (tr, ƒx),

the two-dimensional array S _AMFout (tr, ƒx) of the azimuthal spectra of the azimuthal SF output signal is multiplied line by line by the two-dimensional array S _corr (tr, ƒx) of the correcting functions, and a two-dimensional array S _AMFoutcorr (tr, ƒx) of the corrected azimuthal spectra is obtained,

calculate the inverse FFT line by line along the frequency fx of the two-dimensional array S _AMFoutcorr (tr, ƒx) of the corrected azimuthal spectra, thus obtaining a two-dimensional array U _RLI (tr, ƒx) of complex readouts of the radar image of the underlying surface,

the amplitudes of the complex _{readouts of the} two-dimensional array U _RLI (tr, tx) of the complex _{readouts of the radar image of the} underlying surface are calculated, and a two-dimensional array of the _{radar images of the} underlying surface is obtained I _RLI (tr, tx),

a two-dimensional array I _RLI (tr, tx) of the _{radar image of the} underlying surface is displayed on the radar image of the underlying surface,

the fact that

store a two-dimensional array H _RMF (tr, tx) of impulse characteristics of the range SF for all used sounding radio pulses,

a sounding radio signal is formed with a repetition period and a waveform that is variable from a radio pulse to a radio pulse, determined by the pulse characteristics stored in the two-dimensional array H _RMF (tr, tx) of the pulse characteristics of the long-range SF for all used sounding radio pulses,

The FFT from the impulse responses stored in the columns of the two-dimensional array H _RMF (tr, tx) of the impulse responses of the long-range SF for all radiated probing radio pulses is performed column-wise for all sounding radio pulses, thus obtaining a two-dimensional array S _AMFreƒ (ƒr, tx) of the reference spectra of the range SF for all used sounding radio pulses,

each page of the three-dimensional array S _in (ƒr, tx, n _RG ) of the range spectra of the CRG is element-wise multiplied by the two-dimensional array S _AMFreƒ (ƒr, tx) of the reference spectra of the range SF for all used probing radio pulses,

after receiving a three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG, the sampling period of the azimuthal signals contained in the lines of this array is corrected by resampling the samples of this array along the slow time tx, that is, along the lines, for example, using Lagrange interpolation polynomial

- basic polynomials;

tx _n - irregularly located moments of time at the input of the resampling operation;

tx - regularly located moments of time at the output of the resampling operation;

S _RC (ƒr, tx, n _RG ) - output samples taken at regularly spaced times tx;

S _RC (ƒr, tx _n , n _RG ) - input samples taken at irregularly located moments of time tx _n ;

Ns is the number of input samples used for resampling in the vicinity of the calculated output sample;

n = 0… Ns - the number of the input sample of the resampling operation and the basic polynomial;

m = 0… Ns, except for m ≠ n, is the number of the partial fraction when calculating the basic polynomial;

as a result of which samples are obtained, taken with a uniform sampling period on the slow time axis tx, and only then proceed to the FFT along the slow time tx,

calculate a four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr

perform line-by-line FFT along the slow time tx of the four-dimensional array S _AMFreƒ (ƒr, tx, n _RG , Vr) of the impulse characteristics of the azimuthal SF for all values of the radial velocity Vr, thus obtaining a four-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG , Vr) reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr,

the three-dimensional array of two-dimensional spectra of the range-compressed CRG S _RC (ƒr, ƒx, n _RG ) is multiplied by all three-dimensional subarrays of the four-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG , Vr) of the reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr, obtain in this case, the four-dimensional array S _AMFout (ƒr, ƒx, n _RG , Vr) of the two-dimensional spectra of the azimuthal SF output signal for all values of the radial velocity Vr,

column-wise inverse FFT is performed along the frequency ƒr of the four-dimensional array S _AMFout (ƒr, ƒx, n _RG , Vr) of the two-dimensional spectra of the azimuthal SF output signal for all values of the radial velocity Vr, and a four-dimensional array S _AMFout (tr, ƒx, n _RG , Vr ) azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr,

in each three-dimensional subarray of the four-dimensional array S _AMFout (tr, ƒx, n _RG , Vr) of the azimuthal spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr, the pages are arranged and combined along the first dimension - fast time tr, and a set of pages is obtained that forms three-dimensional array S _AMFout (tr, ƒx, Vr) of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr,

each page of the three-dimensional array S _AMFout (tr, ƒx, n _RG , Vr) of the azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr is element-wise multiplied by the two-dimensional array S _corr (tr, ƒx) of correction functions, thus obtaining a three-dimensional array S _AMFoutcorr (tr, ƒx, Vr) corrected azimuthal spectra for all values of the radial velocity Vr,

calculate a three-dimensional array of azimuthal velocity Vx correcting functions

where R ₀ (tr) is the traverse slant range corresponding to the fast time tr,

each page of the three-dimensional array S _AMFoutcorr (tr, ƒx, Vr) of the corrected azimuthal spectra for all values of the radial velocity Vr is elementwise multiplied by all pages of the three-dimensional array S _corrVx (tr, ƒx, Vx) of the azimuthal velocity Vx correcting functions obtained in this case for each Vr values, three-dimensional arrays arranged along the fourth dimension - the radial velocity Vr, form a four-dimensional array S _AMFoutcorrVx (tr, ƒx, Vx, Vr) azimuthal spectra corrected for the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr,

calculate the inverse FFT line by line along the frequency ƒx of the four-dimensional array S _AMFoutcorrVx (tr, ƒx, Vx, Vr) of the azimuthal spectra corrected by the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr, thus obtaining a four-dimensional array U _RLI (tr, tx, Vx, Vr) of complex readings of radar images of the underlying surface for all values of azimuthal and radial velocities Vx and Vr,

compute the amplitudes of the complex readings of the four-dimensional array U _RLI (tr, tx, Vx, Vr) of the complex readings of the radial image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr, obtain a four-dimensional array of pixels of the radial image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr

calculate a four-dimensional array U _GTh (tr, tx, Vx, Vr) of common thresholds, for example, by the formula

where U _{GTh_comt} is some constant value of the general threshold; or, for example, by the formula

where k _GTh > 1 is the ratio of the excess of the general threshold over the average value of the _{radar image} pixel intensity;

numel (M) - function for determining the number of elements in array M,

calculate a four-dimensional array U _LTh (tr, tx, Vx, Vr) of local thresholds, for example, for each value of the array using the formula

where k _LTh > 1 is the coefficient of excess of the local threshold over the average value of the _{radar image} pixel intensity within the local four-dimensional subarray U _LSA ;

Δtr - fast time increment tr within the local four-dimensional subarray U _LSA ;

Δtx - slow time tx increment within the local four-dimensional subarray U _LSA ;

ΔVx is the increment in the azimuthal velocity of the DC Vx within the local four-dimensional subarray;

ΔVr - increment of the radial velocity of the DC Vr within the local four-dimensional subarray;

summation is performed within the local four-dimensional subarray

defined by rows of values of variables Δtr, Δtx, ΔVx, ΔVr

[Δtr] = -Δtr _max ... Δtr _max provided 0 ≤ (tr + Δtr) <Tr,

[Δtx] = -Δtx _max ... Δtx _max provided 0 ≤ [tx + Δtx) <Tx,

[ΔVx] = -ΔVx _max ... ΔVx _max provided Vx min ≤ (Vx + ΔVx) <Vx max,

[ΔVr] = -ΔVr _max ... ΔVr _max provided Vr min ≤ (Vr + ΔVr) <Vr max;

Δtr _max - maximum value of Δtr;

Δtx _max - maximum value of Δtx;

ΔVx _max - maximum value of ΔVx:

ΔVr _max - maximum value of ΔVr;

Tr is the width of the range of fast time tr values;

Tx is the width of the range of slow time tx values;

Vx min, Vx max - minimum and maximum azimuthal velocities of detected DCs;

Vr min, Vr max - minimum and maximum radial velocities of detected DCs;

- the number of elements in the local four-dimensional subarray U _LSA ,

calculate a four-dimensional array of maxima of neighboring elements

under conditions

where "|" - logical OR;

calculate a four-dimensional array of maximum thresholds

where the maximum is taken element by element between the arrays U _GTh , U _LTh and U _NMTh , compare the values of the elements of the four-dimensional array I _RLI (tr, tx, Vx, Vr) of the _{SAR images of the} underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values of the four-dimensional array U _MTh (tr, tx, Vx, Vr) of the maximum thresholds, while forming a four-dimensional array of DC detection signals

elementwise multiply the elements of the four-dimensional array I _RLI (tr, tx, Vx, Vr) of the _{radar image of the} underlying surface for all values of the azimuthal and radial velocities Vx and Vr by the corresponding elements of the four-dimensional array U _MTD (tr, tx, Vx, Vr) of the DC detection signals, receive a four-dimensional array of radar images of detected DCs

calculate the maximum values of the four-dimensional array I _MT (tr, tx, Vx, Vr) of the radar images of the detected DCs along the dimensions of the radial Vr and azimuthal Vx velocities, thus obtaining a two-dimensional array of the radar images of the detected DCs

display a two-dimensional array of radar images of detected DC I _MT (tr, tx) on the DC indicator.

The invention (device) differs from the closest known analogue [22, 26 ... 31], Fig. 2 containing

bank of impulse characteristics of long-range SF,

the first FFT block along the fast time tr,

digital shaper of the probing radio signal,

analog-digital transmitting and receiving antenna-amplifying system,

digital memory unit TsRG,

block for dividing range elements into groups,

second FFT block along fast time tr,

the first block of multiplication,

the first FFT block along the slow tx time,

block for calculating a three-dimensional array of impulse characteristics of the azimuthal SF

second FFT block along slow tx time,

second multiplication block,

the first block of inverse FFT along the frequency ƒr,

the first block for combining groups of range elements,

block for calculating corrective functions,

third multiplication block,

the first block of the inverse FFT along the frequency ƒx,

the first block for calculating the amplitudes,

radar image indicator of the underlying surface,

in that the device is additionally introduced, FIG. 3,

resampling unit for correcting the sampling period of azimuthal signals, which performs resampling along the slow time tx of samples of a three-dimensional array of spectra compressed in range of the CRG, with input and output,

block for calculating a four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr with output,

the third block of the line-by-line FFT along the slow time tx of the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr with input and output,

the fourth block for multiplying the three-dimensional array of two-dimensional spectra of the range-compressed CRG by three-dimensional subarrays of the four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr with the first and second inputs and outputs,

the second block of the inverse FFT along the frequency ƒr of the four-dimensional array of two-dimensional spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr, with input and output,

the second block for combining groups of range elements, which arranges and combines along the first dimension of the page of three-dimensional subarrays of the four-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr, with input and output,

the fifth multiplication block, which multiplies each page of the three-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr by a two-dimensional array of correcting functions, with the first and second inputs and outputs,

block for calculating Vx azimuthal velocity correcting functions with output,

the sixth multiplication block, which multiplies each page of the three-dimensional array of corrected azimuthal spectra for all values of the radial velocity Vr to all pages of the three-dimensional array of correcting azimuthal velocity Vx functions, with the first and second inputs and outputs,

the second block of the line-by-line inverse FFT along the frequency ƒx of the four-dimensional array of azimuth-corrected azimuth spectra Vx for all values of the azimuthal and radial velocities Vx and Vr, with input and output,

the second block for calculating the amplitudes of the complex readings of the four-dimensional array of complex readouts of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with input and output,

block for calculating a four-dimensional array of common thresholds with input and output,

block for calculating a four-dimensional array of local thresholds with input and output,

block for calculating a four-dimensional array of maxima of neighboring elements with input and output,

block for calculating a four-dimensional array of maximum thresholds with the first, second and third inputs and outputs,

a comparator unit comparing the values of the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx to Vr with the corresponding values of the four-dimensional array of maximum thresholds, with the first and second inputs and outputs,

the seventh multiplication block, elementwise multiplying the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr by the corresponding elements of the four-dimensional array of signals for DC detection, with the first and second inputs and outputs,

a unit for calculating the maximum values of a four-dimensional array of radar images of detected DC along the dimensions of the radial Vr and azimuthal Vx velocities with input and output,

DC indicator displaying a two-dimensional array of radar images of detected DCs, with an input,

moreover

the output of the first multiplication unit is connected to the input of the resampling unit for correcting the sampling period of azimuthal signals, which performs resampling along the slow time tx of samples of the three-dimensional array of spectra compressed in range of the CGD, the output of which is connected to the input of the first FFT unit along the slow time tx, the output of which is connected to the first input of the fourth block for multiplying a three-dimensional array of two-dimensional spectra of the range-compressed CRG into three-dimensional subarrays of a four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr,

the output of the block for calculating the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr is connected to the input of the third block of the line-by-line FFT along the slow time tx of the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr, the output of which is connected to the second input of the fourth block for multiplying the three-dimensional array of two-dimensional spectra of a range-compressed CRG into three-dimensional subarrays of a four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr, the output of which is connected to the input of the second block of the inverse FFT along the frequency ƒr of the four-dimensional array of two-dimensional spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr, whose output is connected to the input of the second block for combining groups of range elements, which builds and combines along the first dimension of the page of three-dimensional subarrays of the four-dimensional array of azimuthal spectra output signal of the azimuthal SF for all values of the radial velocity Vr, the output of which is connected to the first input of the fifth multiplication block, which multiplies each page of the three-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr by a two-dimensional array of correcting functions,

the output of the block for calculating corrective functions is connected to the second input of the fifth multiplication block, which multiplies each page of the three-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr by a two-dimensional array of correcting functions, the output of which is connected to the first input of the sixth multiplication block, which multiplies each page of the three-dimensional an array of corrected azimuthal spectra for all values of the radial velocity Vr on all pages of a three-dimensional array of azimuthal velocity Vx correcting functions,

the output of the block for calculating the azimuthal velocity Vx correcting functions is connected to the second input of the sixth multiplication block, which multiplies each page of the three-dimensional array of corrected azimuthal spectra for all values of the radial velocity Vr to all pages of the three-dimensional array of the azimuthal velocity correcting Vx functions, the output of which is connected to the input of the second block line-by-line inverse FFT along the frequency ƒx of the four-dimensional array of azimuthal spectra corrected by the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr, the output of which is connected to the input of the second block for calculating the amplitudes of complex readouts of the four-dimensional array of complex readouts of the radial image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr, the output of which is connected to the first input of the seventh multiplication block, elementwise multiplying the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values azimuthally th and radial velocities Vx and Vr to the corresponding elements of the four-dimensional array of signals for DC detection, to the first input of the comparator block comparing the values of the elements of the four-dimensional array of radial images of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values of the four-dimensional array of maximum thresholds, which the input of the block for calculating the four-dimensional array of local thresholds, to the input of the block for calculating the four-dimensional array of the maxima of neighboring elements, and to the input of the block for calculating the four-dimensional array of common thresholds, the output of which is connected to the first input of the block for calculating the four-dimensional array of maximum thresholds,

the output of the block for calculating the four-dimensional array of local thresholds is connected to the second input of the block for calculating the four-dimensional array of maximum thresholds,

the output of the block for calculating the four-dimensional array of the maxima of neighboring elements is connected to the third input of the block for calculating the four-dimensional array of maximum thresholds, the output of which is connected to the second input of the comparator block comparing the values of the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values a four-dimensional array of maximum thresholds, the output of which is connected to the second input of the seventh multiplication block, elementwise multiplying the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr by the corresponding elements of the four-dimensional array of signals for DC detection, the output of which is connected to the input of the computing block the maximum values of the four-dimensional array of RI pixels of the detected DC along the dimensions of the radial Vr and azimuthal Vx velocities, the output of which is connected to the input of the DC indicator, is displayed which is a two-dimensional array of radar images of detected DCs.

The set of essential features that distinguish the invention from the closest analogue, in the implementation of the invention, provides the construction of radar images of a fixed underlying surface and the detection of DCs against the background of reflections from the underlying surface in a wide, ambiguous range of survey band when using ultra-wideband sounding radio pulses with a repetition period varying from a radio pulse to a radio pulse and waveform and minimal loss of radar potential tending to zero decibels with increasing duty cycle of sounding radio pulses.

Shown in FIG. 1 synthetic aperture radar using the "Range-Doppler" algorithm, contains:

- bank of impulse characteristics of long-range SF;

- the first FFT block along the fast time tr;

- digital generator of the probing radio signal;

- analog-digital receiving and transmitting antenna-amplifying system;

- memory block TsRG;

- the second FFT block along the fast time tr;

- the first block of multiplication;

- block of inverse FFT along the frequency ƒr;

- the first block of the FFT along the slow tx time;

- block for correction of signal migration by range elements (RCMC);

- block for calculating the impulse characteristics of the azimuthal SF;

- the second block of FFT along the slow tx time;

- the second block of multiplication;

- block of inverse FFT along the frequency ƒx;

- block for calculating amplitudes;

- radar image indicator of the underlying surface.

Shown in FIG. 2 a synthetic aperture radar using the "Omega-K" algorithm contains:

- bank of impulse characteristics of long-range SF (1);

- the first block of FFT along the fast time tr (2);

- digital generator of the probing radio signal (3);

- analog-digital receiving and transmitting antenna-amplifying system (4);

- memory block TsRG (5);

- block for dividing range elements into groups (6);

- the second block of FFT along the fast time tr (7);

- the first block of multiplication (8);

- the first block of the FFT along the slow time tx (9);

block for calculating a three-dimensional array of impulse characteristics of the azimuthal SF (10);

- the second block of the FFT along the slow time tx (11);

- the second block of multiplication (12);

- the first block of the inverse FFT along the frequency ƒr (13);

- the first block for combining groups of range elements (14);

- block for calculating corrective functions (15);

- the third block of multiplication (16);

- the first block of the inverse FFT along the frequency ƒx (17);

- the first block for calculating the amplitudes (18);

- RI indicator of the underlying surface (19).

Shown in FIG. 3 the declared radar with a synthetic aperture of the antenna, which implements the claimed method of radar imaging of the Earth and near-earth space in an ambiguous range in terms of range, with the selection of moving targets against the background of reflections from the underlying surface, contains:

- bank of impulse characteristics of long-range SF (1);

- the first block of FFT along the fast time tr (2);

- digital generator of the probing radio signal (3);

- analog-digital receiving and transmitting antenna-amplifying system (4);

- memory block TsRG (5);

- block for dividing range elements into groups (6);

- the second block of FFT along the fast time tr (7);

- the first block of multiplication (8);

- the first block of the FFT along the slow time tx (9);

block for calculating a three-dimensional array of impulse characteristics of the azimuthal SF (10);

- the second block of the FFT along the slow time tx (11);

- the second block of multiplication (12);

- the first block of the inverse FFT along the frequency ƒr (13);

- the first block for combining groups of range elements (14);

- block for calculating corrective functions (15);

- the third block of multiplication (16);

- the first block of the inverse FFT along the frequency ƒx (17);

- the first block for calculating the amplitudes (18);

- radar image indicator of the underlying surface (19);

- resampling unit for correcting the sampling period of azimuthal signals (20), performing resampling along the slow time tx of samples of a three-dimensional array of spectra compressed in range of the DGC, with input and output;

- block for calculating a four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr (21) with an output,

- the third block of the line-by-line FFT along the slow time tx of the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr (22) with input and output;

- the fourth block for multiplying the three-dimensional array of two-dimensional spectra of the range-compressed CRG into three-dimensional subarrays of the four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr (23) with the first and second inputs and outputs;

- the second block of the inverse FFT along the frequency ƒr of the four-dimensional array of two-dimensional spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr (24) with input and output;

- the second block for combining groups of range elements (25), which builds and combines along the first dimension of the page of three-dimensional subarrays of the four-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr, with input and output;

- the fifth multiplication block (26), which multiplies each page of the three-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr by a two-dimensional array of correcting functions, with the first and second inputs and outputs,

- a block for calculating the azimuthal velocity Vx correcting functions (27) with an output;

- the sixth multiplication block (28), which multiplies each page of the three-dimensional array of corrected azimuthal spectra for all values of the radial velocity Vr by all pages of the three-dimensional array of the azimuthal velocity Vx correcting functions, with the first and second inputs and outputs;

- the second block of a line-by-line inverse FFT along the frequency fix of a four-dimensional array of azimuthal spectra corrected by the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr (29), with input and output,

- the second unit for calculating the amplitudes of complex readings of a four-dimensional array of complex readouts of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr (30) with input and output;

- block for calculating a four-dimensional array of common thresholds (31) with input and output;

- block for calculating a four-dimensional array of local thresholds (32) with input and output;

- block for calculating a four-dimensional array of maxima of adjacent elements (33) with input and output;

- a block for calculating a four-dimensional array of maximum thresholds (34) with the first, second and third inputs and outputs;

- comparator unit (35), comparing the values of the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values of the four-dimensional array of maximum thresholds, with the first and second inputs and outputs;

- the seventh multiplication block (36), elementwise multiplying the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr by the corresponding elements of the four-dimensional array of signals for DC detection, with the first and second inputs and outputs;

- a unit for calculating the maximum values of the four-dimensional array of radar images of the detected DC along the dimensions of the radial Vr and azimuthal Vx velocities (37) with input and output;

- DC indicator (38), displaying a two-dimensional array of radar images of detected DCs, with an input.

Shown in FIG. 4 digital generator of the probing radio signal (3) contains:

- dual-port memory;

- sync pulse generator;

- logical element NOT ("NOT");

- read address counter;

- complex conjugation block;

- key.

Shown in FIG. 5 analog-digital transmitting and receiving antenna-amplifying system (4), built on the basis of one transmitting-receiving antenna, contains:

- digital-radio-frequency converter (TsRCHP);

- transmitting radio frequency amplifier;

- junction point of reception and transmission;

- receiving and transmitting antenna;

- low noise radio frequency amplifier;

- radio frequency-digital converter (RFTsP).

Shown in FIG. 6 DDSP, built according to the scheme with analog conversion of quadrature components, contains:

- digital-to-analog converter (DAC) of the I-component;

- DAC Q-component;

- a low-pass filter (LPF) of the I-component of the transmitting path ("LPF I per.");

- LPF Q- component of the transmitting path ("LPF Q per.");

- quadrature modulator:

- band pass filter (PF) of the transmitting path ("PF per.").

Shown in FIG. 6 RFCP, built according to the scheme with analog shaping of quadrature components, contains:

- PF of the receiving path ("PF pr.");

- quadrature demodulator;

- LPF of the I-component of the receiving path ("LPF I pr.");

- LPF Q- component of the receiving path ("LPF Q pr.");

- analog-to-digital converter (ADC) of the I-component;

- ADC Q-component.

Shown in FIG. 7 DDSH, built according to the scheme with digital transformation of quadrature components, contains:

- digital low-pass filter (DFNCH) of the I-component of the transmitting path ("DFNCH I lane");

- DFNCH Q- component of the transmitting path ("DFNCH Q trans.");

- alternator of the sign of the I-component of the transmitting path;

- alternator of the sign of the Q-component of the transmitting path;

- multiplexer

- DAC;

- band-pass filter of the transmitting path ("PF per.").

Shown in FIG. 7 RFCP, built according to the scheme with digital formation of quadrature components, contains:

- band-pass filter of the receiving path ("PF pr.");

- ADC;

- demultiplexer;

- alternator of the sign of the I-component of the receiving path;

- alternator of the sign of the Q-component of the receiving path;

- ZFNCH of the I- component of the receiving path ("ZFNCH I pr.");

- DFNCH Q- component of the receiving path ("DFNCH Q pr.").

Shown in FIG. 8 analog-digital transmitting and receiving antenna-amplifying system (4), built on the basis of AFAR, contains:

- CDChP;

- power divider;

- adder; -RCHTsP;

- N transceiver modules (TPM), each of which, in turn, contains:

- two switches (P);

- diagramming delay line (LZ);

- diagrammatic attenuator (A);

- transmitting radio frequency amplifier;

- junction point of reception and transmission;

- transceiver emitter;

- low noise radio frequency amplifier.

Shown in FIG. 9 analog-digital transmitting and receiving antenna-amplifying system (4), built on the basis of the CAR, contains:

- digital adder;

- N PPM, each of which, in turn, contains:

- multiplexer (Mux);

- diagram forming digital phase shifter (DPC);

- diagrammatic digital delay line (CLL);

- diagram forming digital attenuator (DA);

- demultiplexer (Demux);

- transmitting correcting digital filter (DF);

- pre-emphasis shaper;

- CDChP;

- transmitting radio frequency amplifier;

- junction node reception-transmission;

- transceiver emitter;

- low noise radio frequency amplifier;

- RFCP;

- receiving corrective CF.

FIG. 10 shows the location of point reflectors (TO) in the survey strip on the plane "azimuth x - slant range r".

FIG. 11 shows the radar image displayed on the radar image indicator of the underlying surface (19).

FIG. 12 shows the marks displayed on the DC indicator (38) of moving TOs detected in a given range of speeds.

Synthetic Aperture Radar, FIG. 3, which implements the method of radar imaging of the Earth and near-earth space in an ambiguous range in terms of range, with the selection of moving targets against the background of reflections from the underlying surface, works as follows.

A pre-calculated two-dimensional array H _RMF (tr, tx) of impulse characteristics of the long-range SF for all used probing radio pulses, which is fed to the output of the considered bank (1), is recorded and stored in the bank of impulse characteristics of the long-range SF (1). Columns of impulse responses in the H _RMF (tr, tx) array are complex conjugate columns of probing radio impulses, mapped from beginning to end.

From the output of the bank of impulse characteristics of the long-range SF (1), the columns of the impulse characteristics of the long-range SF enter the first FFT block along the fast time tr (2) and into the digital shaper of the probing radio signal (3), which forms the probing radio pulse in accordance with the current input column of the impulse characteristics. Each sounding radio pulse has its own waveform, one of the parameters of which is the carrier frequency of the radio pulse in the baseband. The repetition period of radio pulses also varies from radio pulse to radio pulse.

The types of sounding radio pulses used are selected based on the required form of their uncertainty function, which should have the form of either a pushpin, with one pronounced narrow maximum along the axes of the time and Doppler shifts, or the type of a ridge [34 ... 44]. In particular, the following types of radio pulses meet these requirements:

a phase-code-modulated (PCM) radio pulse with a binary sequence;

- linear frequency modulated (LFM) radio pulse;

- nonlinear frequency modulated (NLFM) radio pulse;

- frequency-code-modulated (FCM) radio pulse;

- chirp radio pulse, divided into elements that are randomly mixed on the time axis;

- NLFM radio pulse, divided into elements, which are randomly mixed on the time axis;

- radio noise pulse, which is a sample of noise in the operating frequency range of the radar.

The readings of the sounding radio pulses are calculated using the formulas known from the prior art [34 ... 44].

One of the variants of the digital generator of the probing radio signal (3) is shown in Fig. 4. This digital transmitter of the probing radio signal contains:

- dual-port memory;

- sync pulse generator;

- logical element NOT ("NOT");

- read address counter;

- complex conjugation block;

- key.

The sync pulse generator generates sync pulses, during which sounding radio pulses are formed. In the prototype (Fig. 2), the sync pulse repetition period is constant. In the claimed radar (Fig. 3), the sync pulse repetition period is changed from pulse to pulse. Sync pulses from the output of the sync pulse generator are fed to the logical element NOT and to the control input of the key. After inversion in the logic gate, NOT inverted sync pulses are fed to the input R of the counter of the read address and enable its increment according to the sampling signal with a frequency fs arriving at the input C of this counter. The sampling signal frequency fs is equal to the repetition rate of the generated samples of the quadrature components of the probing radio signal. Formed by the counter of the read address, the inverse read address NOT (A_out), where NOT () is a bitwise operation of logical inversion (NOT), is fed to the input of the read address A_out of the two-port memory, into which the impulse response was previously loaded from the bank of impulse characteristics of the long-range SF range SF, corresponding to the current generated radio pulse. Since the address at the output of the counter of the read address is formed in inverse form, the readings from the dual-port memory through the D_out output are performed in the reverse order. The read out complex readings enter the complex conjugation unit, in which the sign of the complex component Q is reversed, after which complex readings of the current generated sounding radio pulse are obtained, which, through the key opened during the radio pulse duration, go to the output of the digital generator of the sounding radio signal. The digital shaper of the probing radio signal (3) can be constructed according to other schemes [47 ... 53], which does not affect the essence of the claimed invention.

From the output of the digital generator of the probing radio signal (3), the generated digital quadrature readings of the probing radio signal are fed to the input of the analog-digital transmitting and receiving antenna-amplifying system (4), which:

- converts digital quadrature sounding signal to analog form;

- converts the frequency of the quadrature sounding signal from the baseband to the carrier frequency into the operating frequency range;

- enhances the probing radio signal in the operating frequency range;

- emits a probing radio signal in the direction of the removed underlying surface;

- receives the radio signal reflected from the underlying surface;

- amplifies the received radio signal in the operating frequency range;

- converts the frequency of the received radio signal from the operating frequency range to the baseband, thus obtaining a quadrature received signal;

- digitizes the received quadrature signal, while receiving complex readings of the CWG U _in (tr, tx), which is a two-dimensional array of complex readings, where tr is the fast time along the slant range r, and tx is the slow time along the azimuthal coordinate x.

An analog-digital receiving-transmitting antenna-amplifying system (4) can be built in several ways [54 ... 58], for example:

- based on one transmitting and receiving antenna;

- based on the transmitting and receiving active phased antenna array (AFAR);

- on the basis of a transmitting and receiving digital antenna array (CDA).

An analog-digital transceiver antenna-amplifying system (4), built on the basis of one transceiver antenna, shown in FIG. 5, contains:

- digital-radio-frequency converter (TsRCHP);

- transmitting radio frequency amplifier;

- junction point of reception and transmission;

- receiving and transmitting antenna;

- low noise radio frequency amplifier;

- radio frequency-digital converter (RFTsP).

An analog-digital transceiver antenna-amplifier system (4), built on the basis of one transceiver antenna, shown in FIG. 5 works as follows. The digital quadrature readings of the sounding radio signal received at the input of the analog-digital receiving-transmitting antenna-amplifying system (4) from the output of the digital shaper of the probing radio signal (3) are fed to the input of the digital frequency converter, which converts the input signal into an analog form, and also performs frequency conversion from baseband (baseband) to the carrier frequency in the operating frequency range. The transmitting radio-frequency amplifier, the input of which is connected to the output of the digital frequency converter, amplifies in the operating frequency range the probing radio signal arriving at its input from the output of the digital frequency converter. The receive-transmit decoupling unit, built either on the basis of a circulator or on the basis of a radio frequency switch, whose input 1 is connected to the output of the transmitting radio frequency amplifier, connector 2 to the antenna connector, and output 3 to the input of the low noise radio frequency amplifier, transmits the probing radio signal to flow of the transmitting strobe from the output of the transmitting radio frequency amplifier to the transmitting and receiving antenna and transmitting the received radio signal during the receiving strobe from the transmitting and receiving antenna to the low noise radio frequency amplifier. The receiving-transmitting antenna radiates during the transmitting strobe the probing radio signal received from the receiving-transmitting decoupling unit in the direction of the underlying surface being removed and receives during the receiving strobe the radio signal reflected from the underlying surface, which is fed through the transmit-receiving decoupling unit to the input of the low-noise radio-frequency amplifier. A low-noise radio-frequency amplifier amplifies the received radio signal in the operating frequency range during the receiving strobe and outputs an amplified radio signal to its output connected to the RFCP input, which converts in frequency the radio signal received during the receiving strobe from the operating frequency range to the baseband, as well as carries out analog-to-digital conversion, while receiving complex readings of the TsRG U _in (tr, tx), which from the RFTsP output are fed to the output of the described analog-to-digital receive-transmit antenna-amplifier system (4), built on the basis of one transmit-receive antenna ...

DDSP can be built according to schemes with analog or digital transformation of quadrature components, and RFTsP, according to schemes with analog or digital formation of quadrature components [59].

The digital frequency converter, built according to the scheme with analog conversion of quadrature components, shown in FIG. 6, contains:

- DAC I-component;

- DAC Q-component;

- LPF of the I- component of the transmitting path ("LPF I lane");

- LPF Q- component of the transmitting path ("LPF Q per.");

- quadrature modulator:

- PF of the transmitting path ("PF per.").

RFCP, built according to the scheme with analog shaping of quadrature components, shown in FIG. 6, contains:

- PF of the receiving path ("PF pr.");

- quadrature demodulator;

- LPF of the I-component of the receiving path ("LPF I pr.");

- LPF Q- component of the receiving path ("LPF Q pr.");

- ADC I-component;

- ADC Q-component.

DDSP with analog conversion of quadrature components (Fig. 6) works as follows. The IQ input receives digital samples of the I- and Q-quadrature components, which are separately fed to the corresponding “DAC I” and “DAC Q”, where they are converted to analog form, after which they are filtered in the LPF of the I- and Q-channels, respectively. From the outputs of these low-pass filters, the analog quadrature components enter the quadrature modulator, where they are transferred to the operating range, and fed to the bandpass filter of the transmitting path, which cuts off all the parasitic components of the spectrum of the generated probing radio signal outside the operating frequency range. After that, the probing radio signal goes to the "RF output".

RFCP with analog shaping of quadrature components (Fig. 6) works as follows. The received radio signal arriving at the "RF Input" is filtered in the bandpass filter of the receiving path, which cuts off all out-of-band interfering spectrum components. From the output of the bandpass filter, the received radio signal is fed to a quadrature demodulator, which separates the I- and Q-quadrature components, which, after filtering in the low-pass filter of the I- and Q-channels of the receiving path, are digitized into ADC I and ADC Q. From the ADC outputs, digital samples of the quadrature components are combined into one complex digital signal and fed to the "IQ Output".

The digital conversion of quadrature components shown in FIG. 7, contains:

- digital low-pass filter (DFNCH) of the I-component of the transmitting path ("DFNCH I lane");

- DFNCH Q- component of the transmitting path ("DFNCH Q trans.");

- alternator of the sign of the I-component of the transmitting path;

- alternator of the sign of the Q-component of the transmitting path;

- multiplexer

- DAC;

- band-pass filter of the transmitting path ("PF per.").

RFCP, built according to the scheme with digital shaping of quadrature components, shown in Fig. 7, contains:

- band-pass filter of the receiving path ("PF pr.");

- ADC;

- demultiplexer;

- alternator of the sign of the I-component of the receiving path;

- alternator of the sign of the Q-component of the receiving path;

- ZFNCH of the I- component of the receiving path ("ZFNCH I pr.");

- DFNCH Q- component of the receiving path ("DFNCH Q pr.").

DDSP with digital transformation of quadrature components works as follows. The "IQ Input" receives digital samples of the I- and Q-quadrature components, which are separately fed to the corresponding "DSPF I trans." and "ZFNTS Q per.", in which they are filtered, after which in the alternators of the sign of the I- and Q-channels, the sign of the I- and Q- components is changed from sample to sample, respectively. The received components from the outputs of the interleavers are fed to the inputs of the multiplexer, which interleaves them and outputs the resulting stream of samples with a doubled sampling rate to the DAC input, at the output of which an analog signal is formed in several Nyquist zones, which enters the bandpass filter of the transmitting path, where the spectrum components are allocated falling into the operating frequency range. After that, the sounding radio signal formed in the described way is fed to the "RF output".

RFCP with digital shaping of quadrature components works as follows. The received radio signal arriving at the "RF Input" is filtered in the bandpass filter of the receiving path, which cuts off all out-of-band interfering spectrum components. From the output of the bandpass filter, the received radio signal is fed to the ADC, where it is digitized. From the ADC output, samples of the digitized signal are fed to the demultiplexer, which divides them into even and odd. Odd samples go to the I sign alternator of the receiving path, and even ones go to the Q sign alternator of the receiving path. From the outputs of the sign alternators, the I- and Q-quadrature components enter the DSPF I and DSPF Q of the receiving path, in which all high-frequency components of the spectrum that go beyond half the width of the operating frequency range are cut off. Digital samples of the formed quadrature components of the received radio signal from the DSPF outputs are combined into one complex digital signal and fed to the "IQ Output".

An analog-digital transceiver antenna-amplifier system (4) based on the AFAR shown in Fig. 8, contains [60 ... 62]:

- CDChP;

- power divider;

- adder;

- RFCP;

- N transceiver modules (PPM), each of which, in turn, contains:

- two switches (P);

- diagramming delay line (LZ);

- diagrammatic attenuator (A);

- transmitting radio frequency amplifier;

- junction point of reception and transmission;

- transceiver emitter;

- low noise radio frequency amplifier.

Instead of beamforming LPs with a narrow operating frequency range of the radar, beamforming phase shifters can be used.

An analog-digital transceiver antenna-amplifier system (4) based on the AFAR shown in Fig. 8 works as follows. Received at the input of the analog-digital receiving-transmitting antenna-amplifier system (4) from the output of the digital shaper of the probing radio signal (3) digital quadrature readings of the probing radio signal are fed to the input of the digital frequency converter, which, during the transmitting strobe, converts them into analog form, and also performs the conversion in frequency from the baseband to the carrier frequency to the operating frequency range. The probing radio signal received at the output of the digital power divider in the power divider, the input of which is connected to the output of the digital frequency converter, is divided into N directions, where N is the number of BAT in the AFAR, and from each output of the power divider enters the corresponding BAT. In each of the N BAT, the probing radio signal is fed to the right according to the scheme input of the switch "P n.1" (where n = 1 ... N is the BAT number), connected to the corresponding output of the power divider. The output of this switch "П n.1" during the transmitting strobe is switched to the right according to the scheme, and the probing radio signal is fed to the input of the diagrammatic "ЛЗ n" connected to the output of the switch "П n.1", in which it is delayed in time and fed to the output of the specified LZ, which is connected to the input of the diagram-forming attenuator "A n", in which the probing radio signal is regulated in amplitude, and then fed to the output of the specified attenuator connected to the input of the switch "P n.2". The introduced delay and the change in amplitude are selected based on the required shape of the transmitting APAR pattern. The switch "P n.2", turned on during the transmitting strobe to the left according to the scheme, transmits the probing radio signal to its left according to the scheme, the output connected to the input of the transmitting radio-frequency amplifier, which amplifies in the operating frequency range the probing radio signal arriving at its input and outputs it to its output, connected to input 1 of the transmission-reception decoupling node of the considered BAT. The transmit-receive decoupling unit, connector 2 of which is connected to the connector of the transmitting and receiving emitter, and output 3 to the input of the low-noise radio frequency amplifier, transmits the probing radio signal during the transmitting strobe from input 1 to connector 2. The probing radio signal transmitted during the transmitting strobe through the node of decoupling of the receiving-transmitting into the receiving-transmitting emitter, it is emitted into space by the specified receiving-transmitting emitter in the direction of the removed underlying surface. Transmitting emitters of other BAT connected to the power divider emit probing radio signals in the direction of the underlying surface being removed in a similar way, as a result of which a transmitting AP AFAR is formed, the GL of which covers the removed section of the underlying surface.

During the receiving strobe, the transmitting and receiving emitter of the considered NIM receives a radio signal reflected from the underlying surface, which, through the receive-transmit decoupling unit, which transfers the radio signal from connector 2 to output 3 during the receiving strobe, enters the input of a low-noise radio-frequency amplifier, in which it is amplified into operating frequency range and is fed to the output of this amplifier, connected to the left according to the scheme, the input of the switch "P n.1", turned on during the receiving strobe to the left according to the scheme. From the output of the switch "P n.1", the received radio signal is fed to the diagramming delay line "LZ n", delaying the received radio signal, and from its output to the diagramming attenuator "A n", in which the received radio signal is regulated in amplitude. The introduced delay and amplitude change are selected based on the required form of the receiving APAA pattern. From the output of the diagram-forming attenuator through the switch "P n.2", which is switched on during the receiving strobe to the right according to the scheme, the received radio signal is fed to the output of this switch connected to the corresponding input of the adder. The received radio signal received in the adder is summed up with the similar received radio signals of other PPMs. At the output of the adder, a radio signal is received, received by the receiving DP of the AFAR, the GL of which covers the removed area of the underlying surface. The received total received radio signal is fed to the input of the RFTsP connected to the output of the adder. In DDSHP the total received radio signal is converted in frequency from the operating frequency range to the baseband and digitized. At the output of the RFTsP, complex readings of the TsRG U _in (tr, tx) are obtained, which are fed to the output of the described analog-digital receiving-transmitting antenna-amplifying system (4), built on the basis of the AFAR.

An analog-to-digital transceiver antenna-amplifying system (4), based on the DAC, shown in Fig. 9, contains [63 ... 66]:

- digital adder;

- N PPM, each of which, in turn, contains:

- multiplexer (Mux);

- diagram forming digital phase shifter (DPC);

- diagrammatic digital delay line (CLL);

- diagram forming digital attenuator (DA);

- demultiplexer (Demux);

- transmitting correcting digital filter (DF);

- pre-emphasis shaper;

- CDChP;

- transmitting radio frequency amplifier;

- junction node reception-transmission;

- transceiver emitter;

- low noise radio frequency amplifier;

- RFCP;

- receiving corrective CF.

An analog-to-digital transceiver antenna-amplifying system (4), based on the DAC, shown in Fig. 9 works as follows. Entering the input of the analog-digital receiving-transmitting antenna-amplifying system (4) from the output of the digital shaper of the probing radio signal (3) during the transmitting strobe, the quadrature digital samples of the probing radio signal are fed to all GSM, in each of which through the Mux multiplexer, the output of which is connected to the upper input according to the scheme, pass to the diagram-forming DPC, which changes the phase of the transmitted quadrature digital signal, from the output of which it enters the diagram-forming DF, which delays the transmitted quadrature digital signal by a non-integer value of the sampling periods, from the output of which it is fed to the diagram-forming DAC amplitude control of the transmitted quadrature digital signal. The introduced phase change, delay and amplitude change are selected based on the required shape of the transmitting pattern of the CAR. From the output of the diagram-forming DA, digital samples of the probing radio signal through the Demux demultiplexer, the input of which is connected to the upper output according to the circuit during the transmitting strobe, are fed to the input of the transmitting correcting digital filter, which corrects the complex frequency response of the transmitting path of the considered PPM in the operating frequency range. From the output of the transmitting correcting DF, digital samples of the probing radio signal are fed to the predistortioner, which performs preliminary distortion of the transmitted quadrature digital signal, which ensures the operation of the transmitting radio-frequency amplifier in saturation mode without nonlinear distortion of the probing radio signal [67]. From the output of the predistortioner, digital samples of the probing radio signal are fed to the digital frequency converter, which converts them into analog form and converts them in frequency from the baseband to the carrier frequency to the operating frequency range. The probing radio signal received at the output of the DSPP is fed to the transmitting radio-frequency amplifier, which amplifies it in the operating frequency range. From the output of the transmitting radio-frequency amplifier, the probing radio signal passes through the receive-transmit decoupling unit, which transmits the sounding radio signal during the transmitting strobe from the output of the transmitting radio-frequency amplifier to the transmit-receive radiator, and is radiated into space by the specified transmit-receive radiator in the direction of the underlying surface being removed. Receiving-transmitting emitters of other PPMs connected to the input of the considered analog-digital receiving-transmitting antenna-amplifying system (4) emit probing radio signals in the direction of the underlying surface being removed in a similar way, as a result of which a transmitting AP AFAR is formed, the GL of which covers the removed area of the underlying surface. During the receiving strobe, the transmitting and receiving emitter of the considered PPM receives a radio signal reflected from the underlying surface, which enters the receive-transmit decoupling unit, which, during the receiving strobe, transfers the radio signal from the transmitting and receiving radiator to the input of the low-noise radio-frequency amplifier. The received radio signal received at the input of a low-noise radio-frequency amplifier is amplified in the operating frequency range and enters the RFCP, where it is converted in frequency from the operating frequency range to the baseband and digitized. From the output of the RFTsP digital samples of the received radio signal are fed to the receiving correcting DF, which corrects the complex frequency response of the receiving path of the PPM in the operating frequency range. From the output of the receiving correcting digital filter through the Mux n multiplexer, the output of which during the receiving strobe is connected to the lower input according to the circuit, the digital samples of the received radio signal are fed to the diagram-forming chain described above, consisting of the digital filter, the digital signal center and the digital amplifier, in which the phase is changed, the delay is time and change in the signal amplitude for the purpose of diagramming the receiving DN. The introduced phase change, delay and amplitude change are selected based on the required shape of the receiving pattern of the CAR. From the output of the Demux demultiplexer, the input of which during the receiving strobe is connected to the lower output according to the circuit, the digital samples of the received radio signal are fed to the digital adder, where they are summed up with similar digital samples of other PPMs operating in a similar way. At the output of the digital adder, digital readings of the radio signal are formed, received by the receiving DP AFAR, the GL of which covers the removed area of the underlying surface. These digital complex readings represent the CRG U _in (tr, tx), which from the RFCP output is fed to the output of the described analog-to-digital transmitting and receiving antenna-amplifying system (4), built on the basis of the CAR.

In any of the three described analog-to-digital transmit-receive antenna-amplifying systems (4) shown in FIG. 5, figs. 8 and FIG. 9, the radio signal reflected from the underlying surface is premiered during the receiving strobe, which starts after a certain relatively short time interval Δtz after the end of the current transmitting strobe and ends in the same time interval Δtz before the front of the next transmitting strobe. The counts of the CRG that do not fall into the receiving strobe are reset to zero. The height of the TsRG column in the TsRG memory unit (5), that is, the size of the array along the first dimension, is determined by the width of the survey strip along the slant range. In the classical "Omega-k" algorithm (Fig. 2), the maximum value of this width in time is determined by the time interval between the cut of the current sounding radio pulse and the front of the next sounding radio pulse, approximately equal to the repetition period of the sounding radio pulses with a large duty cycle. In the claimed invention, the significantly increased bandwidth of the survey along the slant range in time is several times greater than the average repetition period of sounding radio pulses. Therefore, in each column, there will periodically be sections with zero samples that did not fall into the receiving strobe. Lengths of sections with zero counts equals τ + 2⋅Δt _{zri GI, zri} where τ - duration radio pulse probe, Δt _GI - the duration of the guard time interval. Since the repetition period of the probing radio pulses varies from radio pulse to radio pulse, the positions of the sections with zero readings in each column will be different and the presence of the indicated sections in the CRG will not lead to significant distortion of the radar image of the underlying surface being removed. There will only be a loss of radar potential equal to

where T _PZRI is the average repetition period of sounding radio pulses;

(10 и более) и условии Δt_ЗИ << τ_ЗРИ.which will be close to 0 dB at high duty cycle

(10 and more) and the condition Δt _ЗИ << τ _ЗР .

From the output of the analog-digital receiving-transmitting antenna-amplifying system (4), the TsRG U _in (tr, tx) is fed to the input of the TsRG memory unit (5), which stores the indicated TsRG U _in (tr, tx) during the processing time and its delivery to the output of the specified block (5).

From the output of the TsRG memory unit (5), the stored TsRG U _in (tr, tx) is fed to the input of the unit for dividing range elements into groups (6), in which the TsRG U _in (tr, tx) is divided along the fast time tr into N _RG groups of samples by slant range.

The number of groups of readouts for the slant range can be determined by the formula:

Where

N _RC is the total number of slant range elements in the survey strip;

- the number of readouts (elements) of the slant range in the group of readouts for the slant range;

ceil () - round to the nearest higher integer;

- the maximum width of the group of readouts for the slant range; dR - slant range resolution element width;

- maximum allowable signal migration at the edges of the synthesis interval;

R _BG - slant range of the near border (BG) of the survey strip;

ΔХ _SABG = V _SGLBG ⋅T _SABG is the length of the synthesis path of the antenna aperture for the BG survey strip;

V _СГЛБГ - the speed of the main lobe trail for the BG survey strip;

T _SABG is the synthesis time of the antenna aperture for the BG survey strip.

The choice of the number of groups of readouts for the slant range does not affect the essence of the claimed invention.

After dividing the range elements into groups, a three-dimensional array of complex readouts U _in (tr, tx, n _RG ) is obtained, where n _RG = 1 ... N _RG is the number of the group of readouts along the slant range, which is also the page number in the specified three-dimensional array. The resulting three-dimensional array of complex samples U _in (tr, tx, n _RG } is fed to the output of the considered block (6).

From the output of the block for dividing range elements into groups (6), a three-dimensional array of complex samples U _in (tr, tx, n _RG ) is transmitted to the input of the second FFT block along the fast time tr (7), in which in each group of samples along the slant range of the specified three-dimensional the array of complex samples U _in (tr, tx, n _RG ) perform the FFT along the fast time tr for each column of samples and obtain a three-dimensional array S _in [ƒr, tx, n _RG ) of the CRG range spectra, where ƒr is the range frequency. The resulting array is fed to the output of the considered block (7).

In the first block of the FFT along the fast time tr (2), the FFT from the two-dimensional array H _RMF (tr, tx) of impulse characteristics of the long-range SF for all emitted sounding radio pulses, received at the input of this block (2), is performed column-wise, for all used probing radio pulses. A two-dimensional array S _RMFreƒ (ƒr, tx) of the reference spectra of the range SF for all used probing radio pulses is obtained, which is fed to the output of the unit under consideration (2).

Each page of the three-dimensional array S _in (ƒr, tx, n _RG ) of the range spectra of the CRG arriving at the first input of the first multiplication block (8) from the output of the second FFT block along the fast time tr (7) is element-wise multiplied by the two-dimensional array S _RMFreƒ (ƒr , tx) of the reference spectra of the range SF for all used probing radio pulses, which arrived at the second input of the first multiplication block under consideration (8) from the output of the first FFT block along the fast time tr (2). A three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG is obtained, which is fed to the output of the first multiplication unit under consideration (8).

From the output of the first multiplication unit (8), the three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG is fed to the resampling unit for correcting the sampling period of azimuth signals (20). In this block, the sampling period of the azimuthal signals contained in the lines of this array is corrected by resampling the samples of this array along the slow time tx, that is, along the lines, for example, using the Lagrange interpolation polynomial according to formulas (8) and (9). As a result, samples are obtained, taken with a uniform sampling period on the slow time axis tx, which are written into the same three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG, which in turn is fed to the output of the considered block (20) for further execution of the FFT along the slow time tx.

The three-dimensional array S _RC (ƒr, tx, n _RG ) of range spectra of the range-compressed CRG from the output of the sampling period correction unit for azimuthal signals (20), which performs resampling along the slow time tx of samples of the three-dimensional array of range spectra of the range-compressed CRG, is fed to the input of the first of the FFT block along the slow time tx (9), in which the FFT is performed along the slow time tx from the specified input array, a three-dimensional array S _RC (ƒr, ƒx, n _RG ) of two-dimensional spectra of a range-compressed CRG is obtained, which is fed to the output of the considered block (9) and further, - to the first input of the second multiplication block (12) and to the first input of the fourth block for multiplying the three-dimensional array of two-dimensional spectra of the range-compressed CRG into three-dimensional subarrays of the four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr (23 ).

In the block for calculating the three-dimensional array of impulse characteristics of the azimuthal SF (10) according to the formulas (2) ... (5), the three-dimensional array S _AMFreƒ (ƒr, tx, n _RG ) of the impulse characteristics of the azimuthal SF is calculated, which is fed to the output of the considered block (10), connected to the input of the second FFT block along the slow time tx (11).

In the second block of the FFT along the slow time tx (11), the FFT is performed line by line along the slow time tx from the three-dimensional array S _AMFreƒ (ƒr, tx, n _RG ) of the impulse characteristics of the azimuthal SF received at the input of this block. A three-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG ) of reference two-dimensional spectra of the azimuthal SF is obtained, which is fed to the output of the considered unit (11), connected to the second input of the second multiplication unit (12).

In the second block of multiplication (12), the three-dimensional array S _RC (ƒr, ƒx, n _RG ) of two-dimensional spectra of the range-compressed CRG, received at the first input, is multiplied element by element by the three-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG ) of reference two-dimensional spectra of the azimuthal SF. A three-dimensional array S _AMFout (ƒr, ƒx, n _RG ) of two-dimensional spectra of the azimuthal SF output signal is obtained, which is fed to the output of the considered block (12), connected to the input of the first block of the inverse FFT along the frequency ƒr (13).

In the first block of the inverse FFT along the frequency ƒr (13), a column-wise inverse FFT is performed along the frequency ƒr of the two-dimensional spectra of the azimuthal SF output signal received at the input of the three-dimensional array S _AMFout (ƒr, ƒx, n _RG ). A three-dimensional array S _AMFout (tr, ƒx, n _RG ) of azimuthal spectra of the azimuthal SF output signal is obtained, which is fed to the output of the considered unit (13), connected to the input of the first unit for combining groups of range elements (14).

In the first block for combining the groups of range elements (14), the pages of the three-dimensional array S _AMFout (tr, ƒx, n _RG ) received at the input of the azimuthal spectra of the azimuthal SF output signal are lined up along the first dimension - the fast time tr. A two-dimensional array S _AMFout (tr, ƒx) of azimuthal spectra of the azimuthal SF output signal is obtained, which is fed to the output of the considered unit (14), connected to the first input of the third multiplication unit (16).

In the block for calculating corrective functions (15) according to formula (6), a two-dimensional array S _corr (tr, ƒx) of correcting functions is calculated, which is fed to the output of the considered block (15), connected to the second input of the third multiplication block (16), as well as to the second input of the fifth multiplication block (26).

In the third multiplication block (16), the two-dimensional array S _AMFout (tr, ƒx) of the azimuthal spectra of the output signal of the azimuthal SF received at the first input is multiplied line by line by the two-dimensional array S _corr (tr, ƒx) of correcting functions received at the second input. A two-dimensional array S _AMFoutcorr (tr, ƒx) of corrected azimuthal spectra is obtained, which is fed to the output of the considered block (16) connected to the input of the first block of the inverse FFT along the frequency ƒx (17).

In the first block of the inverse FFT along the frequency ƒx (17), the inverse FFT is calculated line by line along the frequency ƒx from the two-dimensional array S _AMFoutcorr (tr, ƒx) of the corrected azimuthal spectra received at the input of this block. A two-dimensional array U _RLI (tr, tx) of complex readouts of the radar image (RI) of the underlying surface is obtained, which is fed to the output of the considered block (17), connected to the input of the first block for calculating the amplitudes (18).

In the first block for calculating the amplitudes (18) according to the formula (7), the amplitudes of the complex samples of the two-dimensional array U _RLI (tr, tx) of the complex samples of the _{radar image of the} underlying surface received at the input of this block are calculated. A two-dimensional array of pixels of the _{radar image of the} underlying surface I _RLI (tr, tx) is obtained, which is fed to the output of the unit under consideration (18), connected to the input of the _{radar image} indicator of the underlying surface (19).

On the _{radar image} indicator of the underlying surface (19), the two-dimensional array I _RLI (tr, tx) of the _{radar image of the} underlying surface received at the input of the indicated indicator is displayed in the form of pixels on the plane "azimuthal coordinate x - oblique range r" with a brightness level determined by the value of the corresponding element in array I _RLI (tr, tx).

In the block for calculating the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr (21), the four-dimensional array S _AMFreƒ (ƒr, tx, n _RG , Vr) of the impulse characteristics of the azimuthal SF for all values of the radial velocity Vr is calculated, which is is fed to the output of the considered block (21), connected to the input of the third block of the line-by-line FFT along the slow time tx of the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr (22).

The values of the radial velocity Vr of the detected DC in formula (10) are taken from the range Vr min ... Vr max, where Vr min and Vr max are, respectively, the minimum and maximum radial velocities of the detected DC, with a discrete

- коэффициент перекрытия по радиальной скорости;Where

- coefficient of overlap in radial velocity;

D _A is the size of the radar antenna along the track (along the x-axis).

In the third block of the line-by-line FFT along the slow time tx of the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr (22), a line-by-line FFT is performed along the slow time tx of the four-dimensional array S _AMFreƒ (ƒr, tx, n _RG , Vr) of the impulse characteristics of the azimuthal SF for all values of the radial velocity Vr. A four-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG , Vr) of the reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr is obtained, which is fed to the output of the considered block (22), connected to the second input of the fourth block for multiplying the three-dimensional array of two-dimensional spectra range-compressed CRG into three-dimensional subarrays of a four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr (23).

In the fourth block for multiplying the three-dimensional array of two-dimensional spectra of the range-compressed CRG into three-dimensional subarrays of the four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr (23), the three-dimensional array of two-dimensional spectra of the range-compressed CRG S _RC (ƒr, ƒx , n _RG ) to all three-dimensional subarrays of the four-dimensional array S _AMFreƒ (ƒr, ƒx, n _RG , Vr) of the reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr, which arrived at the second input. In this case, a four-dimensional array S _AMFout (ƒr, ƒx, n _RG , Vr) of two-dimensional spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr is obtained, which is fed to the output of the unit under consideration (23) connected to the input of the second block of the inverse FFT along the frequency ƒr a four-dimensional array of two-dimensional spectra of the azimuthal SF output signal for all values of the radial velocity Vr (24).

In the second block of the inverse FFT along the frequency ƒr of the four-dimensional array of two-dimensional spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr (24), a columnar inverse FFT is performed along the frequency ƒr of the four-dimensional array S _AMFout (ƒr, ƒx, n _RG , Vr) of the two-dimensional spectra of the output signal azimuthal SF for all values of the radial velocity Vr. In this case, a four-dimensional array S _AMFout (tr, ƒx, n _RG , Vr) of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr is obtained, which is fed to the output of the considered unit (24), connected to the input of the second unit for combining groups of range elements ( 25).

In the second block for combining the groups of range elements (25) in each three-dimensional subarray of the four-dimensional array S _AMFout (tr, ƒx, n _RG , Vr) of the azimuthal spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr, pages are arranged and combined along the first dimension - fast time tr, thus excluding the third dimension in the array S _AMFout (tr, ƒx, n _RG , Vr). In this case, a set of pages is obtained that forms a three-dimensional array S _AMFout (tr, ƒx, Vr) of the azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr, which is fed to the output of the considered block (25) connected to the first input of the fifth multiplication unit (26 ). The length of the obtained three-dimensional array S _AMFout (tr, ƒx, Vr} along the first dimension corresponds to the width of the entire survey strip.

In the fifth multiplication block (26), each page of the three-dimensional array S _AMFout (tr, ƒx, Vr) of the azimuthal spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr, received at the first input, is multiplied element-wise by the two-dimensional array S _corr (tr, ƒx) corrective functions. A three-dimensional array S _AMFoutcorr (tr, ƒx, Vr) of corrected azimuthal spectra for all values of the radial velocity Vr is obtained, which is fed to the output of the considered unit (26), connected to the first input of the sixth multiplication unit (28).

In the block for calculating the azimuthal velocity Vx correcting functions (27), a three-dimensional array S _corrVx (tr, ƒx, Vx) of the azimuthal velocity Vx correcting functions is calculated by the formula (11), which is fed to the output of the considered block (27) connected to the second input the sixth multiplication block (28).

The values of the azimuthal velocity Vx of the detected DC in formula (11) are taken from the range Vx min ... Vx max, where Vx min and Vx max are respectively the minimum and maximum azimuthal velocities of the detected DC, with a discrete

- коэффициент перекрытия по азимутальной скорости.Where

is the azimuthal velocity overlap coefficient.

In the sixth multiplication block (28), each page of the three-dimensional array S _AMFoutcorr (tr, ƒx, Vr) of the corrected azimuthal spectra received at the first input for all values of the radial velocity Vr is element-wise multiplied by all pages of the three-dimensional array S _corrVx (tr, ƒx , Vx} of the functions correcting for the azimuthal velocity Vx. The three-dimensional subarrays obtained for each value of Vr, arranged along the fourth dimension - the radial velocity Vr, form a four-dimensional array S _AMFoutcorrVx (tr, ƒx, Vx, Vr) corrected for the azimuthal velocity Vx of the azimuthal spectra for all values of the azimuthal and radial velocities Vx and Vr, in which the third dimension corresponds to the azimuthal velocity Vx, and the fourth to the radial velocity Vr. The resulting array is fed to the output of the considered block (28), connected to the input of the second block of the line-by-line inverse FFT along the frequency ƒx of the four-dimensional array of azimuthal velocity corrected Vx azimuthal spectra for all values of azimuthal and radial velocities Vx and Vr (29).

In the second block of the line-by-line inverse FFT along the frequency ƒx of the four-dimensional array of azimuthal spectra corrected for the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr (29), the line-by-line inverse FFT is calculated along the frequency ƒx of the four-dimensional array S _AMFoutcorrVx (tr, Vr ) azimuthal spectra corrected by the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr. At the same time, a four-dimensional array U _RLI (tr, tx, Vx, Vr) of complex readings of the radial image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr is obtained, which is fed to the output of the considered block (29), connected to the input of the second block for calculating the amplitudes of complex readings of a four-dimensional array of complex readouts of radar images of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr (30).

In the second block for calculating the amplitudes of the complex readouts of the four-dimensional array of complex _{readouts of the radar image of the} underlying surface for all values of the azimuthal and radial velocities Vx and Vr (30), using formula (12), the amplitudes of the complex _{readouts of the} four-dimensional array U _RLI (tr, tx, Vx, Vr) of the complex RI readings of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr. At the same time, a four-dimensional array I _RLI (tr, tx, Vx, Vr) of RI pixels of the underlying surface is obtained for all values of the azimuthal and radial velocities Vx and Vr, which is fed to the output of the considered block (30), connected:

- to the input of the block for computing a four-dimensional array of common thresholds (31);

- to the input of the block for calculating the four-dimensional array of local thresholds (32);

- to the input of the block for calculating a four-dimensional array of maxima of neighboring elements (33);

- to the first input of the comparator unit (35);

- to the first input of the seventh multiplication block (36).

In the block for calculating a four-dimensional array of common thresholds (31), for example, using formulas (13) or (14), a four-dimensional array U _GTh (tr, tx, Vx, Vr) of common thresholds is calculated, which is fed to the output of the considered block (31), connected to the first input of the unit for calculating the four-dimensional array of maximum thresholds (34).

In the block for calculating a four-dimensional array of local thresholds (32), a four-dimensional array U _LTh (tr, tx, Vx, Vr) of local thresholds is calculated, for example, for each value of the array according to formulas (15) ... (17). The resulting four-dimensional array U _LTh (tr, tx, Vx, Vr) of local thresholds is fed to the output of the considered block (32), connected to the second input of the block for calculating the four-dimensional array of maximum thresholds (34).

In the block for calculating the four-dimensional array of the maxima of neighboring elements (33) according to the formulas (18) ... (23), the four-dimensional array U _NMTh (tr, tx, Vx, Vr) of the maxima of the neighboring elements is calculated, which is fed to the output of the considered block (33), connected to the third input of the block for calculating the four-dimensional array of maximum thresholds (34).

In the block for calculating the four-dimensional array of maximum thresholds (34), a four-dimensional array U _MTh (tr, tx, Vx, Vr) of maximum thresholds is calculated by the formula (24), which is fed to the output of the considered block (34), connected to the second input of the comparator block (35 ).

In the comparator block (35), the values of the elements of the four-dimensional array I _RLI (tr, tx, Vx, Vr) of the _{radar image of the} underlying surface received at the first input are compared for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values of the four-dimensional array U received at the second input _MTh (tr, tx, Vx, Vr) maximum thresholds. In this case, according to the formula (25), a four-dimensional array U _MTD (tr, tx, Vx, Vr) of DC detection signals is formed, which is fed to the output of the considered block (35), connected to the second input of the seventh multiplication unit (36).

Calculation of four-dimensional arrays of thresholds U _GTh (tr, tx, Vx, Vr), U _LTh (tr, tx, Vx, Vr), U _NMTh (tr, tx, Vx, Vr), U _MTh (tr, tx, Vx, Vr ), produced according to formulas (13) ... (24), can be carried out according to other formulas known from the prior art [66].

In the seventh multiplication block (36), according to formula (26), the elements of the four-dimensional array I _RLI (tr, tx, Vx, Vr) of the _{radar image of the} underlying surface for all values of the azimuthal and radial velocities Vx and Vr are multiplied element by element by the corresponding elements of the at the second input of the four-dimensional array U _MTD (tr, g, tx, Vx, Vr) of the DC detection signals, a four-dimensional array I _MT (tr, tx, Vx, Vr) of the radar images of the detected DCs is obtained, which is fed to the output of the considered block ( 36) connected to the input of the unit for calculating the maximum values of the four-dimensional array of radar images of the detected DC along the dimensions of the radial Vr and azimuthal Vx velocities (37).

In the block for calculating the maximum values of the four-dimensional array of RI pixels of the detected DC along the dimensions of the radial Vr and azimuthal Vx velocities (37), using the formula (27), the maximum values of the four-dimensional array I _MT (tr, tx, Vx, Vr) of the RI pixels of the detected DCs along the dimensions of the radial Vr and azimuthal Vx velocities. A two-dimensional array I _MT (tr, tx) of radar images of detected DCs is obtained, which is fed to the output of the considered block (37), connected to the input of the DC indicator (38).

The DC indicator (38) displays a two-dimensional array of radar images of the detected DCs I _MT (tr, tx) in the form of pixels on the plane "azimuth coordinate x - slant range r" with the brightness level determined by the value of the corresponding element in the array I _MT (tr, tx ).

The mathematical apparatus used in the present invention uses one-dimensional, two-dimensional, three-dimensional and four-dimensional arrays. This mathematical apparatus is widely used in various software systems of computer mathematics, for example, in MATLAB [10, 69 ... 71]. One-dimensional arrays are either columns or rows. Two-dimensional arrays are matrices containing columns and rows, with the index of the matrix element along the first dimension along the column, and the index of the matrix element along the second dimension along the row. The three-dimensional array consists of matrix pages. The page number is the index of the array element along the third dimension. A 4D array is made up of 3D subarrays. The number of a three-dimensional subarray in a four-dimensional array is the index of the array element along the fourth dimension. In all formulas and blocks of the claimed invention, unless otherwise stated, operations with one-dimensional and multidimensional arrays are carried out elementwise. Matrix operations such as matrix-by-matrix, column-by-matrix, matrix-by-column matrix multiplication are not used. The elements of multidimensional arrays are indexed in ascending order of the dimension number, from the lowest first dimension to the highest (second, third, fourth, etc.) dimensions. So, for example, in a four-dimensional array M (i, j, k, m) i is the number of the element in the column, j is the number of the column in the matrix page, k is the number of the matrix page in the three-dimensional subarray, m is the number of the three-dimensional subarray in the four-dimensional array.

Practical implementation of the claimed method of radar survey of the Earth and near-Earth space and a synthetic aperture radar for its implementation is possible on the basis of high-frequency, analog-digital, digital and computing nodes, modules, instrument blocks and systems known from the prior art [72 ... 95].

Digital shaper of the probing radio signal (3), Fig. 3, can be implemented on a programmable logic integrated circuit (FPGA) [75 ... 78]. Analog-digital transceiver antenna-amplifier system (4), Fig. 3, - using high-frequency, analog, analog-to-digital and digital components: FPGAs, digital-to-analog and analog-to-digital converters, radio frequency mixers, quadrature modulators and demodulators, radio frequency amplifiers, radio frequency switches, circulators, radio frequency filters, antenna elements and others components [54 ... 67, 72 ... 78]. All other blocks 1, 2, 5 ... 38 of the radar (Fig. 3) - on an industrial computer (cluster, server or workstation) [79, 80] with graphics accelerators (Graphics Processing Unit, - GPU) based on the "architecture of computational unified devices "CUDA (Compute Unified Device Architecture, - CUDA) [80 ... 95].

In the course of work on the practical confirmation of the performance of the claimed method of radar survey and radar with a synthetic aperture of the antenna, numerical modeling of their work was carried out. The simulation was carried out on a workstation with graphic accelerators (CUDA GPU) in the MATLAB system [69 ... 71]. During the simulation, TOs were placed in the survey strip at different speeds. Thus, in FIG. 10. shows the location of TO in the survey strip on the plane "azimuth x - slant range r", and indicates the azimuthal (VxTO) and radial (VrTO) speeds of their movement. The first TO (lower left on the graph) is stationary, the rest have azimuthal velocities from 125 to 325 m / s. The placed TOs were irradiated with a probing radio signal, the radio signals reflected from the TO were received and formed a CRG, which was then processed by the invented method in the invented radar, Fig. 3. To detect DCs, the range of azimuthal velocities VxTO = 200 ... 250 m / s was set. DCs moving at speeds outside this range should have been detected, but DCs moving at other speeds outside this range should not. As a result, the processing shown in FIG. 11 RI, displayed on the cartographic indicator RI of the underlying surface (19), and presented in Fig. 12 displayed on the DC indicator (38) marks of moving TO, detected in a given range of speeds. In the above figures, nx is the azimuth resolution element number nr is the slant range resolution element number. From FIG. 11 it can be seen that on the indicator (19) only the first stationary TO gives a sharp response. The responses of the others moving along the azimuth of the TO are blurred in azimuth and significantly lower in level. This confirms the disadvantage of the classic "Omega-k" algorithm (prototype, Fig. 2) in the detection of DCs. However, on the DC indicator (38), FIG. 12, one can already see clear marks of three moving TOs, the azimuthal velocities of which fall within the given range of velocities VxTO = 200 ... 250 m / s. The result obtained practically confirms the efficiency of the claimed method of radar survey and synthetic aperture radar.

The program blocks and MATLAB functions debugged during the simulation can be directly used in the implementation of blocks 1, 2, 5 ... 38 of the declared radar.

Information sources

1. David K. Barton, Sergey A. Leonov. Radar technology encyclopedia. - Artech House, Boston, London, 1998.

2. Neronskiy LB, Mikhailov VF, Bragin IV. Microwave equipment for remote sensing of the Earth's surface and atmosphere. Synthetic Aperture Radars / Tutorial / SPbGUAP. SPb., 1999. Part 2. 220 p .: ill.

3. Leonov S.A. Air defense radar. - Moscow: Military Publishing, 1988 .-- 180 p .: ill.

4. Cecil William Farrow. Interpolator for and method of interpolating digital samples. Patent EP 0327268 B1.

5. Cecil William Farrow, "A continuously variable digital delay element," in Proc. IEEE Int. Symp. Circuits and Systems, Espoo, Finland, June 1988, vol. 3, pp. 2641-2645.

6. Ewa Hermanowicz. Weighted Lagrangian interpolating FIR filter. - 8th European Signal Processing Conference (EUSIPCO 1996).

7. V. Valimaki and T.I. Laakso, "Principles of Fractional Delay Filters", - IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP'00), Istanbul, Turkey, 5-9 June 2000.

8. Ewa Hermanowicz. On designing a wideband fractional delay filter using the Farrow approach. - 12th European Signal Processing Conference, 2004.

9. Jeffrey P. Long, Jose A. Torres. High Throughput Farrow Re-samplers Utilizing Reduced Complexity FIR Filters. - 2012 IEEE Military Communications Conference, 29 Oct.-1 Nov. 2012.

10. Michalowski T. Applications of MATLAB in Science and Engineering. - 2nd Edition. - ITexLi, 2017.

11. Bakhvalov H.C., Zhidkov N.P., Kobelkov G.M. Numerical methods. 6th ed. - M .: BINOM. Knowledge laboratory, 2008.

12. Shary. Computational Methods Course. - Novosibirsk, Institute of Computational Technologies SB RAS, 2018.

13. Space-based ground survey radar systems. Ed. V.S. Willows. - M .: Radiotekhnika, 2010 .-- 680 p .: ill.

14. Willow B.C. Detection of ground objects. Airborne radar detection and guidance systems. - M .: Radiotekhnika, 2007 .-- 360 p.: Ill.

15. Neronsky L.B., Osipov I.G., Verba B.C. Modeling the method of spatial-frequency filtering for selection of moving targets in SAR // Proceedings of the XXII All-Russian symposium "Radar study of natural environments". Issue 4. Publishing house Polygraphic center of the Autonomous non-profit organization. Section "Engineering Problems of Stability and Conversion" of the Russian Engineering Academy (SIP RIA). M., 2005.S. 7-15.

16. Neronskiy L., Osipov I., Verba V. Modeling of Space-Frequency Filtering Method for Moving Target Indication in SAR // Proc. of EUSAR'2006, Dresden, Germany. June 16-18 2006

17. J.R. Bennett and I.G. Cumming, "A Digital Processor for the Production of SEASAT Synthetic Aperture Radar Imagery", SURGE Work-shop, 1979

18. I.G. Cumming and J.R. Bennett, "Digital Processing of SEASAT SAR Data", IEEE International Conference on Acoustics, Speech and Signal Processing, Washington, D.C., 1979.

19. A.M. Smith, "A New Approach to Range Doppler SAR Processing", International Journal of Remote Sensing, vol. 12 (2), pp. 235-251, 1991.

20. R. Bamler, "A Systematic Comparison Of SAR Focusing Algorithms", International Geoscience and Remote Sensing Symposium, IGARSS, vol. 2, pp. 1005-1009, 1991.

21. R. Bamler, "A Comparison of Range-Doppler and Wavenumber Domain SAR Focusing Algorithms", IEEE Transactions on Geoscience and Remote Sensing, vol. 30 (4), pp. 706-713, 1992.

22. Ian G. Cumming, Frank H. Wong. Digital Processing of Synthetic Aperture Radar Data: Algorithms and Implementation, 1st ed. Artech House Publishers, Boston, London, 2005.

23. Dan Wang, Murtaza Ali. Synthetic Aperture Radar on low power multi-core Digital Signal Processor. - Waltham, MA, USA, 2012 IEEE Conference on High Performance Extreme Computing

24. Wang D., Ali M., Blinka E. Synthetic Aperture Radar (SAR) Implementation on a TMS320C6678 Multicore DSP. SPRY276. - Texas, Dallas: Texas Instruments Incorporated, 2015.

25. Airborne reconnaissance radar systems, decoding of radar images: a textbook for cadets of the Air Force Academy named after Professor N.Ye. Zhukovsky. Ed. L.A. School. - M .: ed. VVIA them. Prof. N.E. Zhukovsky, 2008.

26. Stolt R.H. Migration by Fourier transform. - Geophysics, vol. 43, no. 1 (february 1978); P. 23-48, 26 figs.

27. Claudio Prati, Fabio Rocca, Andrea Monti Guarnieri, Elvio Damonti. Seismic migration for SAR focusing: Intereferometrical Applications. - IEEE Transactions on geoscience and remote sensing, vol. 28, no. 4, July 1990.

28. Cafforio C., Prati C., Rocca E. SAR data focusing using seismic migration techniques. - IEEE Transactions on Aerospace and Electronic Systems, vol. 27, no. 2, March 1991.

29. Richard Bamler. A Comparison of Range-Doppler and Wavenumber Domain SAR Focusing Algorithms. - IEEE Transactions on Geoscience and Remote Sensing, Vol. 30, No. 4, July 1992.

30. David W. Hawkins. Synthetic Aperture Imaging Algorithms: with application to wide bandwidth sonar. - A thesis presented for the degree of Doctor of Philosophy in Electrical and Electronic Engineering at the University of Canterbury, Christchurch, New Zealand, October 1996.

31. Tsvetkov O.E. Algorithms for processing signals in SAR with migration along the range channels. Digital signal processing in SAR. Collection of scientific articles. Ed. Tolstova E.F. - Military Academy of Military Air Defense of the Armed Forces of the Russian Federation, Smolensk, 2005.

32. Weinberg Graham. Radar Detection Theory of Sliding Window Processes. - CRC Press, 2017 .-- 401 p.

33. Beletsky Yu.S. Methods and algorithms for contrast detection of signals against the background of interference with a priori unknown characteristics. Monograph. - M .: "Radiotekhnika", 2011.

34. Wackman D.E. Complex signals and the principle of uncertainty in radar. - Moscow, "Soviet Radio", 1965.

35. Varakin L.Ye. Complex signal theory. - Moscow, "Soviet Radio", 1970.

36. Cook Ch., Bernfeld M. Radar signals. Per. from English ed. V.S. Kelson. - Moscow, "Soviet Radio", 1971.

37. Wackman D.E., Sedletsky P.M. Synthesis of radar signals. - Moscow, "Soviet Radio", 1973.

38. Ipatov. Periodic discrete signals with optimal correlation properties. 1992.

39. Levanov N., Mozeson E. Radar Signals. - Hoboken, New Jersey, John Wiley & Sons, Inc., 2004.

40. Gantmakher B.E., Bystrov H.E., Chebotarev D.V. Noise-like signals. - SPb .: Science and Technology, 2005.

41. Golomb S. W., Gong G. Signal Desing for Good Correlation. - Cambridge University Press, 2005.

2009.42. An M., Brodzik AK, Tolimieri R. Ideal Sequence Design in Time-Frequency Space. Applications to Radar, Sonar, and Communication Systems. -

2009.

43. Potekhin E.H. Synthesis and analysis of optimal binary sequences. Dissertation for the degree of candidate of physical and mathematical sciences, specialty 05.13.17 (Theoretical foundations of computer science). - Yoshkar-Ola, PSTU, 2014.

44. Bodrov O.A. Synthesis of phase-and frequency-shift keyed signals in radio engineering systems. - M .: Hotline - Telecom, 2016.

45. Golomb S.W. Shift Register Sequences. Secure and Limited-Access Code Generators, Efficiency Code Generators, Prescribed Property Generators, Mathematical Models. 3rd revised edition. - Singapore: World Scientific, 2017.

46. Chapursky B.B. Selected problems of the theory of ultra-wideband radar systems. 3rd ed., Rev. - Moscow: Publishing house of MSTU im. N.E. Bauman, 2017.

47. Crawford J.A. Frequency Synthesizer Design Handbook. - New York: Artech House, 1994 .-- 456 p.

48. Ridiko L.I. DDS: Direct Digital Frequency Synthesis - Components and Technologies, No. 7, No. 8 2001.

49. Yampurin NP, Boloznev VV, Safonova EV, Zhalnin E.B. Formation of precision frequencies and signals. - Nizhny Novgorod, Nizhny Novgorod. state tech. un-t, 2003.

50. Belov L. Synthesizers of stable frequencies. - Electronics: Science, Technology, Business, No. 3 2004.

51. Steven Eugene Turner, Richard T. Chan and Jeffrey T. Feng. ROM-Based Direct Digital Synthesizer at 24 GHz Clock Frequency in InP DHBT Technology. - IEEE Microwave and Wireless Components Letters, vol. 18, No. 8, August 2008.

52. Chenakin A. Frequency Synthesizers: From Concept to Product. - New York: Artech House, 2010 .-- 305 p.

53. Gaopeng Chen, Danyu Wu, Zhi Jin, Jin Wu and Xinyu Liu. A 10GHz 8-bit Direct Digital Synthesizer implemented in GaAs HBT technology. - 2010 IEEE Radio Frequency Integrated Circuits Symposium, pp. 425-428.

54. Lo Y.T., Lee S.W. Antenna Handbook. Theory, Applications, and Design. - New York, Springer Science + Business Media, LLC, 1988.

55. Voskresensky D.I., Gostyukhin V.L., Maksimov V.M., Ponomarev L.I. Microwave Devices and Antennas / Ed. DI. Voskresensky. Ed. 2nd, add. and revised - M .: Radio engineering, 2006.

56. Allen B., Dohler M., Okon EE, Malik W.Q., Brown A.K., Edwards D.J. Ultra-wideband Antennas and Propagation for Communications, Radar and Imaging. - John Wiley & Sons Ltd, 2007.

57. Constantine A. Balanis. Antenna Theory. Analysis and Design. Fourth edition. - John Wiley & Sons, Inc., Hoboken, New Jersey, 2016.

58. Chen Z.N., Liu D., Nakano H., Qing X., Zwick Th. (Eds.) Handbook of Antenna Technologies (4 Volume Set). - Springer Science + Business Media, Singapore, 2016 .-- 3470 p.

59. Lyons P. Digital Signal Processing: Second Edition. Per. from English. - M .: OOO "Binom-Press", 2006.

60. Van Trees H.L. Detection, Estimation, and Modulation Theory. Part 4. Optimum Array Processing. - John Wiley, 2002 .-- 1470 p.

61. Microwave devices and antennas. Design of phased antenna arrays: Textbook. manual for universities / Ed. DI. Voskresensky. Ed. 4th, rev. and add. - M .: Radiotekhnika, 2012, - 744 p .: ill.

62. Hansen R.S. Phased antenna arrays. Second edition. - Moscow: Technosphere, 2012.

63. Grigoriev L.N. Digital beamforming in phased array antennas. - M .: Radio engineering, 2010.

64. Voskresensky D.I., Ovchinnikova E.V., Shmachilin P.A. Onboard digital antenna arrays and their elements / Ed. DI. Voskresensky. - M .: Radiotekhnika, 2013.

65. Dobychina EM, Koltsov Yu.V. Digital antenna arrays in airborne radar systems. - M .: Publishing house MAI, 2013.

66. Ponomarev L.I., Vechtomov V.A., Miloserdov A.S. Onboard digital multi-beam antenna arrays for satellite communication systems / ed. L.I. Ponomarev. - Moscow: Publishing house of MSTU im. N.E. Bauman, 2016.

67. Fischer R.F.H. Precoding and Signal Shaping for Digital Transmission. - Springer, 2002 .-- 507 p.

68. Giuseppe A. Fabrizio. High Frequency Over-the-Horizon Radar: Fundamental Principles, Signal Processing and Practical Applications. - Moscow: Technosphere, 2018.

69. Anufriev I.E., Smirnov A.B., Smirnova E.N. MATLAB 7.- SPb .: BHV-Petersburg, 2005.

70. Dyakonov V.P. MATLAB. Complete tutorial. - M .: DMK Press, 2012.

71. MATLAB Mathematics. - The Math Works, Inc. 2017.

72. Chang K. Encyclopedia of RF and Microwave Engineering. - Wiley-Interscience, 2005 .-- 5832 p.

73. Weiner M.M. Adaptive Antennas and Receivers. - CRC Press, 2006 .-- 1206 p.

74. Tsui James, Cheng Chi-Hao. Digital Techniques for Wideband Receivers. 3rd Ed. - SciTech Publishing, 2017 .-- 610 p.

75.http: //www.xilinx.com

76. https://www.intel.com

77. Rodger H. Hosking. Putting FPGAs to Work in Software Radio Systems. Seven Edition. - Pentec, Inc., 2013.

78. Vanderbauwhede W., Benkrid K. High-Performance Computing Using FPGAs. - Springer, 2014 .-- 803 p.

79. Antonopoulos N., Gillam L. Cloud Computing. Principles, Systems and Applications. - Springer, 2010.

80.http: //www.nvidia.com

81. Chapman B. et al. Parallel Computing: From Multicores and GPU's to Petascale. - IOS Press, 2010 .-- 761 p.

82. Jimmy Pettersson, Ian Wainwright. Radar Signal Processing with Graphics Processors (GPUs). Company Unclassified Master Thesis. - SAAB, 2010.

83. Hwu W.W. GPU Computing Gems: Emerald Edition. - Morgan Kaufmann, 2011 .-- 886 p.

84. Hwu W.W. GPU Computing Gems Jade Edition. - Applications of GPU Computing Series. - Morgan Kaufmann, 2011 .-- 560 p.

85. Jakub Kurzak, David A. Bader, Jack Dongarra. Scientific Computing with Multicore and Accelerators. - CRC Press, Taylor & Francis Group, 2011.

86. David B. Kirk, Wenmei W. Hwu. Programming massively parallel processors. A Hand-on Approach. Second Edition. - Elsevier Inc., 2013.

87. Cook Shane. CUDA Programming: A Developer's Guide to Parallel Computing with GPUs. - Morgan Kaufmann, 2013 .-- 600 p.

88. Wilt N. The CUDA handbook. A Comprehensive Guide to GPU Programming. - Pearson Education, Inc. 2013 .-- 522 p.

89. Suh J.W., Kim Y. Accelerating MATLAB with GPU Computing: A Primer with Examples. - Morgan Kaufmann, 2014 .-- 247 p.

90. Rose Chris. CUDA Succinctly. - Morrisville, Syncfusion Inc, 2014.

91. John Cheng, Max Grossman, Tu McKercher. Professional CUDA With Programming. - John Wiley & Sons, Inc., 2014.

92. Ploskas N., Samaras N. GPU Programming in MATLAB. - Morgan Kaufmann, 2016 .-- 320 p.

93. Nekrasov K.A., Potashnikov S.I., Boyarchenkov A.S., Kupryazhkin A.Ya. General Purpose Parallel Computing on GPUs: A Tutorial. - Yekaterinburg: Publishing house Ural, university, 2016.

94. Hamid Sarbazi-Azad. Advances in GPU Research and Practice. - Morgan Kaufmann, 2017.

95. Soyata T. GPU Parallel Program Development Using CUDA. - New York: Chapman and Hall / CRC, 2018 .-- 477 p.

Claims (162)

1. A method of radar survey of the Earth and near-Earth space by a synthetic aperture radar (SAR) in a band of ambiguous range with selection of moving targets against the background of reflections from the underlying surface, which is that store the column H _RMF (tr) of the impulse response of the range matched filter (SF) for the used sounding radio pulse, form a sounding radio signal with a fixed repetition period of the same sounding radio pulses corresponding to the impulse response stored in the column H _RMF (tr) of the impulse response of the range SF for the used sounding radio pulse, and emit this radio signal in the direction of the underlying surface being removed using an analog-digital receiving and transmitting antenna -amplifier system, the radio signal reflected from the underlying surface is received using an analog-to-digital receiving-transmitting antenna-amplifying system and a digital radio hologram (TsRH) U _in (tr, tx) is obtained, which is a two-dimensional array of complex readings, where tr is the fast time along the slant range r, a tx - slow time along the azimuthal coordinate x, CRG U _in (tr, tx) is divided along the fast time tr into N _RG groups of readouts along the slant range, thus obtaining a three-dimensional array of complex readouts U _in (tr, tx, n _RG ), where n _RG is the number of the group of readouts by the slant range which is also the number of pages in the specified 3D array, in each group of readouts along the slant range in a three-dimensional array of complex samples U _in (tr, tx, n _RG ), a fast Fourier transform (FFT) is performed along the fast time tr for each column of samples and a three-dimensional array S _in (ƒr, tx, n _RG ) of the CRG range spectra, where ƒr is the range frequency, FFT is performed from the stored column H _RMF (tr) of the impulse response of the range SF for the used sounding radio pulse, and the column S _RMFref (ƒr) of the reference spectrum of the range SF is obtained, the columns of the three-dimensional array S _in (ƒr, tx, n _RG ) of the range spectra of the CRG are elementwise multiplied by the column S _RMFref (ƒr) of the reference spectrum of the range SF, thus obtaining a three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra compressed in range TsRG, FFT is performed along the slow time tx of the three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG, thus obtaining a three-dimensional array S _RC (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the range-compressed CRG, calculate a three-dimensional array of impulse responses of the azimuthal SF

Where

- the multiplier of blanking the temporary support function;

- normalized end-to-end radiation pattern (DP) of the SAR antenna;

- imaginary unit;

- the reference phase function of the azimuthal SF versus the slow time tx for the range frequency ƒr and the number of the group of range elements n _RG ;

- the central value of the slow time tx; T _CA - time of synthesis of the aperture; ΔΘ _GL0 is the width of the main lobe (GL) of the SAR antenna antenna at the zero power level; V _SGL is the speed of movement of the GL track of the AP antenna of the SAR on the underlying surface; R ₀ (n _RG ) - traverse slant range of the center of the group of range elements with the number n _RG ; c is the speed of propagation of electromagnetic waves in vacuum; ƒ _ЗРС - carrier frequency of the probing radio signal; perform line-by-line FFT along the slow time tx of the three-dimensional array S _AMFref (ƒr, tx, n _RG ) of the impulse characteristics of the azimuthal SF, thus obtaining a three-dimensional array S _AMFref (ƒr, ƒx, n _RG ) of the reference two-dimensional spectra of the azimuthal SF, the three-dimensional array S _RC (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the range-compressed CRG is elementwise multiplied by the three-dimensional array S _AMFref (ƒr, ƒx, n _RG ) of the reference two-dimensional spectra of the azimuthal SF, and a three-dimensional array S _AMFout (ƒr, ƒx , n _RG ) of the two-dimensional spectra of the azimuthal SF output signal, a column-wise inverse FFT of the three-dimensional array S _AMFout (ƒr, ƒx, n _RG ) of the two-dimensional spectra of the output signal of the azimuthal SF along the frequency ƒr is performed, thus obtaining a three-dimensional array S _AMFout (tr, ƒx, n _RG ) of the azimuthal spectra of the output signal of the azimuthal SF, pages of the three-dimensional array S _AMFout (tr, ƒx, n _RG ) of the azimuthal spectra of the azimuthal SF output signal are aligned along the first dimension - fast time tr, thus obtaining a two-dimensional array S _AMFout (tr, ƒx) of the azimuthal spectra of the azimuthal SF output signal, calculate a two-dimensional array of correcting functions

where λ is the wavelength of the probing radio signal; R ₀ (n _RSG ) - traverse slant range of the center of the subgroup of range elements with number n _RSG ; ƒx is the frequency of the azimuthal signal along the slow tx time; the two-dimensional array S _AMFout (tr, ƒx) of the azimuthal spectra of the azimuthal SF output signal is multiplied line by line by the two-dimensional array S _corr (tr, ƒx) of the correcting functions, and a two-dimensional array S _AMFoutcorr (tr, ƒx) of the corrected azimuthal spectra is obtained, calculate the inverse FFT line by line along the frequency ƒx of the two-dimensional array S _AMFoutcorr (tr, ƒx) of the corrected azimuthal spectra, thus obtaining a two-dimensional array U _RLI (tr, tx) of complex readouts of the radar image (RI) of the underlying surface, calculate the amplitudes of the complex _{readouts of the} two-dimensional array U _RLI (tr, tx) of the complex _{readouts of the radar image of the} underlying surface, thus obtaining a two-dimensional array of pixels of the radar image of the underlying surface I _RLI (tr, tx) = 20lg (| U _RLI (tr, tx) |) a two-dimensional array I _RLI (tr, tx) of the _{radar image of the} underlying surface is displayed on the radar image of the underlying surface, characterized in that store a two-dimensional array H _RMF (tr, tx) of impulse characteristics of the range SF for all used sounding radio pulses, a sounding radio signal is formed with a repetition period and a waveform that is variable from a radio pulse to a radio pulse, determined by the pulse characteristics stored in the two-dimensional array H _RMF (tr, tx) of the pulse characteristics of the long-range SF for all used sounding radio pulses, The FFT from the impulse responses stored in the columns of the two-dimensional array H _RMF (tr, tx) of the impulse responses of the long-range SF for all emitted sounding radio pulses is performed column-wise for all sounding radio pulses, thus obtaining a two-dimensional array S _RMFref (ƒr, tx) of the reference spectra of the range SF for all used radio sounding pulses, each page of the three-dimensional array S _in (ƒr, tx, n _RG ) of the range spectra of the CRG is elementwise multiplied by the two-dimensional array S _RMFref (ƒr, tx) of the reference spectra of the range SF for all used sounding radio pulses, after receiving a three-dimensional array S _RC (ƒr, tx, n _RG ) of the range spectra of the range-compressed CRG, the sampling period of the azimuthal signals contained in the lines of this array is corrected by resampling the samples of this array along the slow time tx, that is, along the lines, for example, using Lagrange interpolation polynomial

Where

- basic polynomials; tx _n - irregularly located moments of time at the input of the resampling operation; tx - regularly located moments of time at the output of the resampling operation; S _RC (ƒr, tx, n _RG ) - output samples taken at regularly spaced times tx; S _RC (ƒr, tx _n , n _RG ) - input samples taken at irregularly located moments of time tx _n ; Ns is the number of input samples used for resampling in the vicinity of the calculated output sample; n = 0… Ns - the number of the input sample of the resampling operation and the basic polynomial; m = 0… Ns, except for m ≠ n, is the number of the partial fraction when calculating the basic polynomial; as a result of which samples are obtained, taken with a uniform sampling period on the slow time axis tx, and only then proceed to the FFT along the slow time tx, calculate a four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr

perform line-by-line FFT along the slow time tx of the four-dimensional array S _AMFref (ƒr, tx, n _RG , Vr) of the impulse characteristics of the azimuthal SF for all values of the radial velocity Vr, thus obtaining a four-dimensional array S _AMFref (ƒr, ƒx, n _RG , Vr) reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr, the three-dimensional array of two-dimensional spectra of the range-compressed CRG S _RC (ƒr, ƒx, n _RG ) is multiplied by all three-dimensional subarrays of the four-dimensional array S _AMFref (ƒr, ƒx, n _RG , Vr) of the reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr, obtain in this case, the four-dimensional array S _AMFout (ƒr, ƒx, n _RG , Vr) of the two-dimensional spectra of the azimuthal SF output signal for all values of the radial velocity Vr, column-wise inverse FFT is performed along the frequency ƒr of the four-dimensional array S _AMFout (ƒr, ƒx, n _RG , Vr) of the two-dimensional spectra of the azimuthal SF output signal for all values of the radial velocity Vr, and a four-dimensional array S _AMFout (tr, ƒx, n _RG , Vr ) azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr, in each three-dimensional subarray of the four-dimensional array S _AMFout (tr, ƒx, n _RG , Vr) of the azimuthal spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr, the pages are arranged and combined along the first dimension, the fast time tr, and a set of pages is obtained that forms a three-dimensional array S _AMFout (tr, ƒx, Vr) of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr, each page of the three-dimensional array S _AMFout (tr, ƒx, Vr) of the azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr is elementwise multiplied by the two-dimensional array S _cjrr (tr, ƒx) of the correction functions, thus obtaining the three-dimensional array S _AMFoutcorr (tr, ƒx, Vr) of the corrected azimuthal spectra for all values of the radial velocity Vr, calculate a three-dimensional array of azimuthal velocity Vx correcting functions

where R ₀ (tr) is the traverse slant range corresponding to the fast time tr, each page of the three-dimensional array S _AMFoutcorr (tr, ƒx, Vr) of the corrected azimuthal spectra for all values of the radial velocity Vr is elementwise multiplied by all pages of the three-dimensional array S _corrVx (tr, ƒx, Vx) of the azimuthal velocity Vx correcting functions obtained in this case for each Vr values, three-dimensional arrays arranged along the fourth dimension - the radial velocity Vr, form a four-dimensional array S _AMFoutcorrVx (tr, ƒx, Vx, Vr) azimuthal spectra corrected for the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr, calculate the inverse FFT line by line along the frequency ƒx of the four-dimensional array S _AMFoutcorrVx (tr, ƒx, Vx, Vr) of the azimuthal spectra corrected by the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr, thus obtaining a four-dimensional array U _RLI (tr, tx, Vx, Vr) of complex readings of radar images of the underlying surface for all values of azimuthal and radial velocities Vx and Vr, compute the amplitudes of the complex readings of the four-dimensional array U _RLI (tr, tx, Vx, Vr) of the complex readings of the radial image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr, obtain a four-dimensional array of pixels of the radial image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr I _RLI (tr, tx, Vx, Vr) = 20⋅lg (| U _RLI (tr, tx, Vx, Vr) |), calculate a four-dimensional array U _GTh (tr, tx, Vx, Vr) of common thresholds, for example, according to the formula U _GTh (tr, tx.Vx, Vr) = U _{GTh_const} , where U _{GTh_const} is some constant value of the common threshold; or, for example, by the formula

where k _GTh > 1 is the ratio of the excess of the general threshold over the average value of the _{radar image} pixel intensity; numel (M) - function for determining the number of elements in array M; calculate a four-dimensional array U _LTh (tr, tx, Vx, Vr) of local thresholds, for example, for each value of the array using the formula

where k _LTh > 1 is the coefficient of excess of the local threshold over the average value of the _{radar image} pixel intensity within the local four-dimensional subarray U _LSA ; Δtr - fast time increment tr within the local four-dimensional subarray U _LSA ; Δtx - slow time tx increment within the local four-dimensional subarray U _LSA ; ΔVx is the increment in the azimuthal velocity of moving targets (DC) Vx within the local four-dimensional subarray; ΔVr - increment of the radial velocity of the DC Vr within the local four-dimensional subarray; the summation is carried out within the local four-dimensional subarray U _LSA = [Δtr] & [Δtx] & [ΔVx] & [ΔVr], defined by the rows of values of the variables Δtr, Δtx, ΔVx, ΔVr, [Δtr] = - Δtr _max ... Δtr _max subject to 0≤ (tr + Δtr) <Tr, [Δtx] = - Δtx _max ... Δtx _max under the condition 0≤ (tx + Δtx) <Tx, [ΔVx] = - ΔVx _max ... ΔVx _max provided Vx min≤ (Vx + ΔVx) <Vx max, [ΔVr] = - ΔFr _max ... ΔFr _max , provided Vr min≤ (Vr + ΔVr) <max; Δtr _max - maximum value of Δtr; Δtx _max - maximum value of Δtx; ΔVx _max - maximum value of ΔVx; ΔVr _max - maximum value of ΔVr; Tr is the width of the range of fast time tr values; Tx is the width of the range of slow time tx values; Vx min, Vx max - minimum and maximum azimuthal velocities of detected DCs; Vr min, Vr max - minimum and maximum radial velocities of detected DCs; N _LSA = (2Δtr _max +1) ⋅ (2Δtx _max +1) ⋅ (2ΔVx _max +1) ⋅ (2ΔVr _max +1) - the number of elements in the local four-dimensional subarray U _LSA ; calculate a four-dimensional array of maxima of neighboring elements

under conditions (Δtr ≠ 0) | (Δtx ≠ 0) | (ΔVx ≠ 0) | (ΔVr ≠ 0), where "|" - logical OR, 0≤ (tr + Δtr) <Tr, 0≤ (tx + Δtx) <Tx, Vx min≤ (Vx + ΔVx) <Vx max, Vr min≤ (Vr + ΔVr) <Vr max, calculate a four-dimensional array of maximum thresholds U _MTh (tr, tx, Vx, Vr) = max [U _GTh (tr, tx, Vx, Vr), U _LTh (tr, tx, Vx, Vr), U _NMTh (tr, tx, Vx, Vr)], where the maximum is taken element by element between arrays U _GTh , U _LTh and U _NMTh , comparing the values of the elements of the four-dimensional array I _RLI (tr, tx, Vx, Vr) of the _{radar images of the} underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values of the four-dimensional array U _MTh (tr, tx, Vx, Vr) of the maximum thresholds, form in this case, a four-dimensional array of signals for detecting moving targets (DC) U _MTD (tr, tx, Vx, Vr) = (I _RLI (tr, tx, Vx, Vr)> U _MTh (tr, tx, Vx, Vr)), elementwise multiply the elements of the four-dimensional array I _RLI (tr, tx, Vx, Vr) of the _{radar image of the} underlying surface for all values of the azimuthal and radial velocities Vx and Vr by the corresponding elements of the four-dimensional array U _MTD (tr, tx, Vx, Vr) of the DC detection signals, receive a four-dimensional array of radar images of detected DCs I _MT (tr, tx, Vx, Vr) = I _RLI (tr, tx, Vx, Vr) ⋅U _MTD (tr, tx, Vx, Vr), calculate the maximum values of the four-dimensional array I _MT (tr, tx, Vx, Vr) of the radar images of the detected DCs along the dimensions of the radial Vr and azimuthal Vx velocities, thus obtaining a two-dimensional array of the radar images of the detected DCs

display a two-dimensional array of radar images of detected DC I _MT (tr, tx) on the DC indicator. 2. Radar with a synthetic aperture antenna, implementing the method of claim 1, containing bank of impulse characteristics of long-range SF, the first FFT block along the fast time tr, the input of which is connected to the output of the bank of impulse characteristics of the long-range SF, digital generator of the probing radio signal, the input of which is connected to the output of the bank of impulse characteristics of the long-range SF, an analog-digital receiving-transmitting antenna-amplifying system, the input of which is connected to the output of the digital generator of the probing radio signal, memory unit TsRG, the input of which is connected to the output of the analog-digital receive-transmit antenna-amplifier system, a unit for dividing range elements into groups, the input of which is connected to the output of the TsRG memory unit, the second FFT block along the fast time tr, the input of which is connected to the output of the block for dividing range elements into groups, the first multiplication block, the first input of which is connected to the output of the second FFT block along the fast time tr, and the second input to the output of the first FFT block along the fast time tr, the first FFT block along the slow tx time, block for calculating a three-dimensional array of impulse characteristics of the azimuthal SF the second FFT block along the slow time tx, the input of which is connected to the output of the block for calculating a three-dimensional array of impulse responses of the azimuthal SF, the second multiplication block, the first input of which is connected to the output of the first FFT block along the slow time tx, and the second input to the output of the second FFT block along the slow time tx, the first block of the inverse FFT along the frequency ƒr, the input of which is connected to the output of the second block of multiplication, the first block for combining groups of range elements, the input of which is connected to the output of the first block of the inverse FFT along the frequency ƒr, block for calculating corrective functions, the third multiplication block, the first input of which is connected to the output of the first block for combining groups of range elements, and the second input to the output of the block for calculating corrective functions, the first block of the inverse FFT along the frequency ƒx, the input of which is connected to the output of the third block of multiplication, the first block for calculating the amplitudes, the input of which is connected to the output of the first block of the inverse FFT along the frequency ƒx, the radar image indicator of the underlying surface, the input of which is connected to the output of the first block for calculating the amplitudes, characterized in that the device additionally introduced resampling unit for correcting the sampling period of azimuthal signals, which performs resampling along the slow time tx of samples of a three-dimensional array of range spectra compressed in range of the DGC, with input and output, block for calculating a four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr with output, the third block of the line-by-line FFT along the slow time tx of the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr with input and output, the fourth block for multiplying the three-dimensional array of two-dimensional spectra of the range-compressed CRG by three-dimensional subarrays of the four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr with the first and second inputs and outputs, the second block of the inverse FFT along the frequency ƒr of the four-dimensional array of two-dimensional spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr with input and output, the second block for combining groups of range elements, which arranges and combines along the first dimension of the page of three-dimensional subarrays of the four-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr, with input and output, the fifth multiplication block, which multiplies each page of the three-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr by a two-dimensional array of correcting functions, with the first and second inputs and outputs, block for calculating Vx azimuthal velocity correcting functions with output, the sixth multiplication block, which multiplies each page of the three-dimensional array of corrected azimuthal spectra for all values of the radial velocity Vr to all pages of the three-dimensional array of correcting azimuthal velocity Vx functions, with the first and second inputs and outputs, the second block of the line-by-line inverse FFT along the frequency ƒx of the four-dimensional array of azimuthal spectra corrected for the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr with input and output, the second block for calculating the amplitudes of the complex readings of the four-dimensional array of complex readouts of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with input and output, block for calculating a four-dimensional array of common thresholds with input and output, block for calculating a four-dimensional array of local thresholds with input and output, block for calculating a four-dimensional array of maxima of neighboring elements with input and output, block for calculating a four-dimensional array of maximum thresholds with the first, second and third inputs and outputs, a comparator unit comparing the values of the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values of the four-dimensional array of maximum thresholds, with the first and second inputs and outputs, the seventh multiplication block, elementwise multiplying the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr by the corresponding elements of the four-dimensional array of signals for DC detection, with the first and second inputs and outputs, a unit for calculating the maximum values of a four-dimensional array of radar images of detected DC along the dimensions of the radial Vr and azimuthal Vx velocities with input and output, DC indicator displaying a two-dimensional array of radar images of detected DCs, with an input, moreover the output of the first multiplication unit is connected to the input of the resampling unit for correcting the sampling period of azimuthal signals, which performs resampling along the slow time tx of samples of the three-dimensional array of range spectra of the range-compressed CRG, the output of which is connected to the input of the first FFT unit along the slow time tx, the output of which is connected to the first input the fourth block for multiplying the three-dimensional array of two-dimensional spectra of the range-compressed CRG by three-dimensional subarrays of the four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr, the output of the block for calculating the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr is connected to the input of the third block of the line-by-line FFT along the slow time tx of the four-dimensional array of impulse characteristics of the azimuthal SF for all values of the radial velocity Vr, the output of which is connected to the second input of the fourth block for multiplying the three-dimensional array of two-dimensional spectra of a range-compressed CRG into three-dimensional subarrays of a four-dimensional array of reference two-dimensional spectra of the azimuthal SF for all values of the radial velocity Vr, the output of which is connected to the input of the second block of the inverse FFT along the frequency ƒr of the four-dimensional array of two-dimensional spectra of the output signal of the azimuthal SF for all values of the radial velocity Vr, whose output is connected to the input of the second block for combining groups of range elements, which builds and combines along the first dimension of the page of three-dimensional subarrays of the four-dimensional array of azimuthal spectra output signal of the azimuthal SF for all values of the radial velocity Vr, the output of which is connected to the first input of the fifth multiplication block, which multiplies each page of the three-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr by a two-dimensional array of correcting functions, the output of the block for calculating corrective functions is connected to the second input of the fifth multiplication block, which multiplies each page of the three-dimensional array of azimuthal spectra of the azimuthal SF output signal for all values of the radial velocity Vr by a two-dimensional array of correcting functions, the output of which is connected to the first input of the sixth multiplication block, which multiplies each page of the three-dimensional an array of corrected azimuthal spectra for all values of the radial velocity Vr on all pages of a three-dimensional array of azimuthal velocity Vx correcting functions, the output of the block for calculating the azimuthal velocity Vx correcting functions is connected to the second input of the sixth multiplication block, which multiplies each page of the three-dimensional array of corrected azimuthal spectra for all values of the radial velocity Vr to all pages of the three-dimensional array of the azimuthal velocity correcting Vx functions, the output of which is connected to the input of the second block line-by-line inverse FFT along the frequency ƒx of the four-dimensional array of azimuthal spectra corrected by the azimuthal velocity Vx for all values of the azimuthal and radial velocities Vx and Vr, the output of which is connected to the input of the second block for calculating the amplitudes of complex readouts of the four-dimensional array of complex readouts of the radial image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr, the output of which is connected to the first input of the seventh multiplication block, elementwise multiplying the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values azimuthally th and radial velocities Vx and Vr to the corresponding elements of the four-dimensional array of signals for DC detection, to the first input of the comparator block comparing the values of the elements of the four-dimensional array of radial images of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values of the four-dimensional array of maximum thresholds, which the input of the block for calculating the four-dimensional array of local thresholds, to the input of the block for calculating the four-dimensional array of maxima of neighboring elements and to the input of the block for calculating the four-dimensional array of common thresholds, the output of which is connected to the first input of the block for calculating the four-dimensional array of maximum thresholds, the output of the block for calculating the four-dimensional array of local thresholds is connected to the second input of the block for calculating the four-dimensional array of maximum thresholds, the output of the block for calculating the four-dimensional array of the maxima of neighboring elements is connected to the third input of the block for calculating the four-dimensional array of maximum thresholds, the output of which is connected to the second input of the comparator block comparing the values of the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr with the corresponding values a four-dimensional array of maximum thresholds, the output of which is connected to the second input of the seventh multiplication block, elementwise multiplying the elements of the four-dimensional array of pixels of the radar image of the underlying surface for all values of the azimuthal and radial velocities Vx and Vr by the corresponding elements of the four-dimensional array of signals for DC detection, the output of which is connected to the input of the computing block the maximum values of the four-dimensional array of RI pixels of the detected DC along the dimensions of the radial Vr and azimuthal Vx velocities, the output of which is connected to the input of the DC indicator, is displayed a two-dimensional array of radar images of detected DCs, wherein the bank of impulse characteristics of the long-range SF stores and outputs to its output a two-dimensional array of impulse characteristics of the long-range SF for all used probing radio pulses, the digital generator of the probing radio signal generates a probing radio signal with a repetition period and a waveform that is variable from a radio pulse to a radio pulse, determined by the impulse characteristics contained in the columns of the two-dimensional array of impulse characteristics of the long-range SF for all used probing radio pulses, the first FFT block along the fast time tr performs the FFT column-wise for all columns of the two-dimensional array of impulse characteristics of the long-range SF for all radiated probing radio pulses, and outputs a two-dimensional array of reference spectra of the long-range SF for all used probing radio pulses, and the first multiplication unit element-wise multiplies the pages of the three-dimensional array of the range spectra of the CRG arriving at its first input by the two-dimensional array of reference spectra of the range SF for all used probing radio pulses arriving at the second input.

Images